Drive mechanism for drug delivery pumps with integrated status indication

ABSTRACT

A drive mechanism includes a housing, a piston adapted to impart movement to a plunger seal within a drug container, a plurality of biasing members disposed in parallel, and a retainer. The biasing members are disposed to release energy to cause movement of the piston from a retracted first position to the extended second position, the piston bearing against the plunger seal to dispense medicine. The retainer is disposed to maintain the biasing members in the energized position and to release the biasing members to permit the piston to dispense the medicine. The drive mechanism may also include an end-of-dose indicator to identify at least one of when the sleeve assembly is disposed subjacent a window in the housing the relative motion of the sleeve assembly with reference to the window or another reference component, the stoppage of such motion, and the rated or change of rate of motion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/230,784 filed Mar. 31, 2014, which is a continuation-in-part ofP.C.T. Application PCT/US2014/013005 and U.S. application Ser. No.14/163,690, both filed Jan. 24, 2014, and which both claim priority toU.S. Provisional Application 61/756,667, filed on Jan. 25, 2013, andU.S. Provisional Application 61/912,642, filed Dec. 6, 2013. U.S.application Ser. No. 14/163,690 is also a continuation-in-part of U.S.application Ser. No. 13/600,114, filed Aug. 30, 2012, which claimspriority to U.S. Provisional Application 61/530,788 filed Sep. 2, 2011.This application claims priority to each of these applications, each ofwhich is incorporated by reference herein in its entirety for allpurposes.

FIELD

This invention relates to drug delivery pumps. More particularly, thisinvention relates to drive mechanisms with integrated status indication,drug delivery pumps with status integrated drive mechanisms, the methodsof operating such devices, and the methods of assembling such devices.

BACKGROUND

Parenteral delivery of various drugs, i.e., delivery by means other thanthrough the digestive track, has become a desired method of drugdelivery for a number of reasons. This form of drug delivery byinjection may enhance the effect of the substance being delivered andensure that the unaltered medicine reaches its intended site at asignificant concentration. Similarly, undesired side effects associatedwith other routes of delivery, such as systemic toxicity, canpotentially be avoided through parenteral delivery. By bypassing thedigestive system of a mammalian patient, one can avoid degradation ofthe active ingredients caused by the catalytic enzymes in the digestivetract and liver and ensure that a necessary amount of drug, at a desiredconcentration, reaches the targeted site.

Traditionally, manually operated syringes and injection pens have beenemployed for delivering parenteral drugs to a patient. More recently,parenteral delivery of liquid medicines into the body has beenaccomplished by administering bolus injections using a needle andreservoir, continuously by gravity driven dispensers, or via transdermalpatch technologies. Bolus injections often imperfectly match theclinical needs of the patient, and usually require larger individualdoses than are desired at the specific time they are given. Continuousdelivery of medicine through gravity-feed systems compromises thepatient's mobility and lifestyle, and limits the therapy to simplisticflow rates and profiles. Another form of drug delivery, transdermalpatches, similarly has its restrictions. Transdermal patches oftenrequire specific molecular drug structures for efficacy, and the controlof the drug administration through a transdermal patch is severelylimited.

Ambulatory infusion pumps have been developed for delivering liquidmedicaments to a patient. These infusion devices have the ability tooffer sophisticated fluid delivery profiles accomplishing bolusrequirements, continuous infusion and variable flow rate delivery. Theseinfusion capabilities usually result in better efficacy of the drug andtherapy and less toxicity to the patient's system. Currently availableambulatory infusion devices are expensive, difficult to program andprepare for infusion, and tend to be bulky, heavy and very fragile.Filling these devices can be difficult and require the patient to carryboth the intended medication as well as filling accessories. The devicesoften require specialized care, maintenance, and cleaning to assureproper functionality and safety for their intended long-term use, andare not cost-effective for patients or healthcare providers.

As compared to syringes and injection pens, pump type delivery devicescan be significantly more convenient to a patient, in that doses of thedrug may be calculated and delivered automatically to a patient at anytime during the day or night. Furthermore, when used in conjunction withmetabolic sensors or monitors, pumps may be automatically controlled toprovide appropriate doses of a fluidic medium at appropriate times ofneed, based on sensed or monitored metabolic levels. As a result, pumptype delivery devices have become an important aspect of modern medicaltreatments of various types of medical conditions, such as diabetes, andthe like.

While pump type delivery systems have been utilized to solve a number ofpatient needs, manually operated syringes and injection pens oftenremain a preferred choice for drug delivery as they now provideintegrated safety features and can easily be read to identify the statusof drug delivery and the end of dose dispensing. However, manuallyoperated syringes and injections pens are not universally applicable andare not preferred for delivery of all drugs. There remains a need for anadjustable (and/or programmable) infusion system that is precise andreliable and can offer clinicians and patients a small, low cost, lightweight, simple to use alternative for parenteral delivery of liquidmedicines.

SUMMARY

The present invention provides drive mechanisms with integrated statusindication, drug delivery pumps which incorporate such drive mechanisms,the methods of operating such devices, and the methods of assemblingsuch devices. The drive mechanisms of the present invention provideintegrated status indication features which provide feedback to the userbefore, during, and after drug delivery. For example, the user may beprovided an initial feedback to identify that the system is operationaland ready for drug delivery. Upon activation, the system may thenprovide one or more drug delivery status indications to the user. Atcompletion of drug delivery, the drive mechanism and drug pump mayprovide an end-of-dose indication. As the end-of-dose indication is tiedto the piston reaching the end of its axial translation, the drivemechanism and drug pump provide a true end-of-dose indication to theuser. Additionally, the embodiments of the present invention provideend-of-dose compliance to ensure that substantially the entire drug dosehas been delivered to the user and that the status indication featureshave been properly contacted to provide accurate feedback to the user.Through these mechanisms, confirmation of drug dose delivery canaccurately be provided to the user or administrator. Accordingly, thenovel devices of the present invention alleviate one or more of theproblems associated with prior art devices, such as those referred toabove.

In a first embodiment, the present invention provides a drive mechanismhaving integrated status indication which includes: a drive housing, astatus switch interconnect, a drive biasing member, a piston, and a drugcontainer having a cap, a pierceable seal, a barrel, and a plunger seal.The drive biasing member may be configured to bear upon an interfacesurface of the piston. The drug container may preferably contain a drugfluid for delivery to the user. The drive mechanism may further includea connection mount attached to the pierceable seal. A cover sleeve maybe utilized between the drive biasing member and the interface surfaceof the piston to, for example, provide more even distribution of forcefrom the biasing member to the piston. A contact sleeve may be slidablymounted to the drive housing through an axial aperture of the drivehousing, such that sleeve hooks at a distal end of the contact sleeveare caused to contact the piston between interface surface and a contactprotrusion near the proximal end of the piston. The piston may alsoinclude a locking groove, between contact protrusion and the proximalend of the piston. The contact sleeve may have a radially extending ringat its proximal end, upon which reside one or more flex prongs.

The drive mechanism may further include one or more contact surfaceslocated on corresponding components. Such contact surfaces may beelectrical contact surfaces, mechanical contact surfaces, orelectro-mechanical contact surfaces. Such surfaces may initially be incontact and caused to disengage, or initially be disconnected and causedto engage, to permit a signal to be sent to and/or from the powercontrol system. In at least one embodiment, as described further herein,the contact surfaces may be electrical contact surfaces which areinitially disconnected and caused to come into engagement whereby, uponsuch engagement, contact surfaces are capable of continuing an energypathway or otherwise relaying a signal to the power and control system.In another embodiment of the present invention, the contact surfaces aremechanical contact surfaces which are initially in contact and caused todisengage whereby, upon such disengagement, such disengagement iscommunicated to the power and control system. Such signals may betransferred across one or more interconnects to the power and controlsystem or by mechanical action to the power and control system. Suchcomponents may be utilized within the drive mechanism to measure andrelay information related to the status of operation of the drivemechanism, which may be converted by the power and control system intotactile, auditory, and/or visual feedback to the user. Regardless of theelectrical or mechanical nature of the contact surfaces, the motion ofthe components which permits transmission of a signal to the powercontrol system is enabled by a biasing member axially translating acontact sleeve in the distal direction during operation of the device.

The drive mechanism may include a piston extension slidably mounted at adistal end and within an axial pass-through of piston; a pistonextension biasing member, which is mounted within the axial pass-throughof piston and initially compressed between piston extension and piston;and, optionally, a piston biasing member support between pistonextension biasing member and piston extension. The piston extension isretained within piston by interaction between one or more extension armsof the piston extension and one or more corresponding connection slotsof piston. The piston extension may be utilized to perform a compliancepush of drug fluid from the drug container. Additionally oralternatively, the drive mechanism may utilize a compressible plungerseal, wherein such compression capacity or distance permits a compliancepush of drug fluid from the drug container. Other compliance featuresare described further herein.

In another embodiment of the present invention, a drive mechanism havingintegrated incremental status indication includes a drive housing, adrive biasing member, a piston, an incremental status stem having a steminterconnect mounted, affixed, printed, or otherwise attached thereon,and a drug container having a cap, a pierceable seal, a barrel, and aplunger seal, wherein the incremental status stem resides within axialpass-throughs of the drive housing and the piston. The incrementalstatus stem may have one or more interconnects which contact one or morecontacts on the piston to provide incremental status feedback to theuser. The incremental status embodiment may similarly utilize theelectrical, mechanical, or electro-mechanical interconnects andcontacts, and/or one or more of the compliance features, describedabove.

In a further embodiment, the present invention provides a drug deliverypump with integrated status indication. The drug pump includes a housingand an assembly platform, upon which an activation mechanism, aninsertion mechanism, a fluid pathway connection, a power and controlsystem, and a drive mechanism having a drug container may be mounted.The drive biasing member may be configured to bear upon an interfacesurface of the piston. The drug container may preferably contain a drugfluid for delivery to the user. The drive mechanism may further includea connection mount attached to the pierceable seal. A cover sleeve maybe utilized between the drive biasing member and the interface surfaceof the piston to, for example, provide more even distribution of forcefrom the biasing member to the piston. A contact sleeve may be slidablymounted to the drive housing through an axial aperture of the drivehousing, such that sleeve hooks at a distal end of the contact sleeveare caused to contact the piston between interface surface and a contactprotrusion near the proximal end of the piston. The piston may alsoinclude a locking groove, between contact protrusion and the proximalend of the piston. The contact sleeve may have a radially extending ringat its proximal end, upon which reside one or more flex prongs. Thedrive mechanism may further include one or more contact surfaces locatedon corresponding components. Such contact surfaces may be electricalcontact surfaces, mechanical contact surfaces, or electro-mechanicalcontact surfaces. Such surfaces may initially be in contact and causedto disengage, or initially be disconnected and caused to engage, topermit a signal to be sent to and/or from the power control system. Inat least one embodiment, as described further herein, the contactsurfaces may be electrical contact surfaces which are initiallydisconnected and caused to come into engagement whereby, upon suchengagement, contact surfaces are capable of continuing an energy pathwayor otherwise relaying a signal to the power and control system. Inanother embodiment of the present invention, the contact surfaces aremechanical contact surfaces which are initially in contact and caused todisengage whereby, upon such disengagement, such disengagement iscommunicated to the power and control system. Regardless of theelectrical or mechanical nature of the contact surfaces, the motion ofthe components which permits transmission of a signal to the powercontrol system is enabled by a biasing member axially translating acontact sleeve in the distal direction during operation of the device.

In yet another embodiment, the present invention provides a drugdelivery pump with incremental status indication. The drug pump includesa housing and an assembly platform, upon which an activation mechanism,an insertion mechanism, a fluid pathway connection, a power and controlsystem, and a drive mechanism having a drug container may be mounted,and further includes an incremental status stem having a steminterconnect mounted, affixed, printed, or otherwise attached thereon,wherein the incremental status stem resides within axial pass-throughsof the drive housing and the piston, and wherein the incremental statusstem has one or more interconnects which contact one or more contacts onthe piston to complete an transmission to the power and control systemto provide incremental feedback to the user. The drug delivery pump withincremental status indication may similarly utilize the electrical,mechanical, or electro-mechanical interconnects and contacts, and/or oneor more of the compliance features, described above.

The present invention further provides a method of assembly. The drugcontainer may first be assembled and filled with a drug fluid. The drugcontainer includes a cap, a pierceable seal, a barrel, and a plungerseal. The pierceable may be fixedly engaged between the cap and thebarrel, at a distal end of the barrel. The barrel may be filled with adrug fluid through the open proximal end prior to insertion of theplunger seal from the proximal end of the barrel 58. An optionalconnection mount may be mounted to a distal end of the pierceable seal.The connection mount to guide the insertion of the piercing member ofthe fluid pathway connection into the barrel of the drug container. Thedrug container may then be mounted to a distal end of drive housing.

Prior to mounting the drug container to the housing, a switch statusinterconnect may be mounted to a proximal end of drive housing. Acontact sleeve, having one or more sleeve hooks at a distal end and aring at a proximal end having an electrical contact thereon, may bemounted to the drive housing through an axial pass-through from theproximal end of the drive housing. A drive biasing member may beinserted into a distal end of the drive housing. Optionally, a coversleeve may be inserted into a distal end of the drive housing tosubstantially cover biasing member. A piston may be inserted into thedistal end of the drive housing and through an axial pass-through ofcontact sleeve, such that a contact protrusion of piston is proximal tothe sleeve hooks of contact sleeve. The piston and drive biasing member,and optional cover sleeve, may be compressed into the drive housing.Such assembly positions the drive biasing member in an initialcompressed, energized state and preferably places a piston interfacesurface in contact with the proximal surface of the plunger seal withinthe proximal end of barrel. When a piston extension is employed, thepiston extension and piston extension biasing member, and optionalpiston biasing member support, may be compressed into an axialpass-through of piston prior to compression of the components. Prior to,or after, installing these components into the drive mechanism housing,the primary container may be attached.

When one or more interconnects or contacts are utilized for statusindication, such components may be mounted, connected, printed, orotherwise attached to their corresponding components prior to assemblyof such components into the drive mechanism. When a separate incrementalstatus stem and a corresponding stem interconnect are utilized for suchincremental status indication, the stem interconnect may be mounted,affixed, printed, or otherwise attached to incremental status stem priorto assembly of the incremental status stem to the proximal end of thecontact sleeve and/or the proximal end of the drive housing in a mannersuch that the incremental status stem resides within an axialpass-through of contact sleeve and drive housing. The incremental statusstem is further mounted to reside within an axial pass-through ofpiston.

The disclosure describes, in one aspect, a drug pump drive mechanism foruse in cooperation with a drug container including a plunger seal. Thedrive mechanism has an axis and includes a drive housing, a pistonadapted to impart movement to the plunger seal within the drugcontainer, a plurality of biasing members disposed in parallel, and aretainer. The piston is disposed for movement from a retracted firstposition along the axis to an extended second position. The biasingmembers are adapted to move from an energized first position to adeenergized second position as a result of the release of energy. Thebiasing members are disposed to cause movement of the piston from theretracted first position to the extended second position as the biasingmembers move from the energized first position to the deenergized secondposition. The retainer is disposed to maintain the biasing members inthe energized first position when the retainer is in a retaining firstposition, and to release the biasing members from the first energizedposition when the retainer moves to a releasing second position.

In at least one embodiment, the plurality of biasing members includes atleast one of a tension spring or a compression spring. In at least oneembodiment, the plurality of biasing members includes a pair of springs,in at least one embodiment of which the springs are compression springs.In at least embodiment, the compression springs are concentricallydisposed, and disposed about at least a portion of the piston. In atleast one embodiment, the retainer engages at least a portion of thepiston to retain the piston in its retracted position when the retaineris in its retaining first position. At least one embodiment furtherincludes a sleeve assembly disposed about at least one of the pluralityof biasing members. In at least one embodiment, the sleeve assemblyincludes a plurality of telescoping sleeves, and the sleeve assembly isdisposed to move to axially with the piston. At least one embodimentfurther includes at least one window and at least a portion of thesleeve assembly is visible through the window with at least a portion ofthe sleeve assembly being visible through the window until the piston isin the extended second position. At least one embodiment furtherincludes an end-of-dose indicator disposed substantially adjacent thewindow, the end-of-dose indicator being adapted to identify at least oneof when the sleeve assembly is disposed subjacent the window and whenthe sleeve assembly is not disposed subjacent the window, the relativemotion of the sleeve assembly with reference to the window or anotherreference component, the stoppage of such motion, and the rate or changeof rate of motion. In at least one embodiment, the end-of-dose indicatorincludes a sensor disposed to sense at least one of when the sleeveassembly is disposed subjacent the window and when the sleeve assemblyis not disposed subjacent the window. In at least one embodiment, thesensor is a mechanical sensor, an electrical sensor, an ultrasonicsensor, a capacitive sensor, a magnetic sensor, or an optical sensor. Inat least one embodiment, the sensor is a mechanical sensor disposed tobear against the sleeve assembly when the sleeve assembly is disposedsubjacent the window.

In another aspect of the disclosure, there is provided a drug pump drivemechanism for use in cooperation with a drug container including aplunger seal; the drive mechanism has an axis and includes a drivehousing, a piston adapted to impart movement to the plunger seal withinthe drug container, at least one biasing member, a retainer, a sleeveassembly, and an end-of-dose indicator. The piston is disposed formovement from at least a retracted first position to an extended secondposition along the axis. The at least one biasing member is disposed andadapted to move from an energized first position to a deenergized secondposition as a result of the release of energy. The biasing member isdisposed to cause movement of the piston from the retracted firstposition to the extended second position as the biasing member movesfrom the energized first position to the deenergized second position.The retainer disposed to maintain the biasing member in the energizedfirst position when the retainer is in a retaining first position, andto release the biasing member from the first energized position when theretainer moves to a releasing second position. The sleeve assembly isadapted to move along the axis with the piston. The sleeve assembly isdisposed at least partially within the drive housing, and at least aportion of the sleeve assembly being visible through a window in thehousing when the piston is one of the retracted first position or theextended second position. The sleeve assembly is not visible through thewindow when the piston is in the other of the retracted first positionor the extended second position. The end-of-dose indicator is disposedsubstantially adjacent the window. The end-of-dose indicator is adaptedto identify at least one of when the sleeve assembly is disposedsubjacent the window and when the sleeve assembly is not disposedsubjacent the window.

In at least one embodiment, the sleeve assembly is disposed about the atleast one biasing member and includes a plurality of telescopingsleeves. In an embodiment, the sleeve assembly is disposed about thebiasing member(s). In at least one embodiment, the at least one biasingmember includes a plurality of biasing members. A particular embodimentincludes at least two compression springs disposed in parallel. In atleast on embodiment, the end-of-dose indicator includes a sensordisposed to sense at least one of when the sleeve assembly is disposedsubjacent the window and when the sleeve assembly is not disposedsubjacent the window. In at least one embodiment, the sensor is at leastone of a mechanical sensor, a mechanical sensor, an electrical sensor,an ultrasonic sensor, a capacitive sensor, a magnetic sensor, or anoptical sensor. In a particular embodiment, the sensor is a mechanicalsensor disposed to bear against the sleeve assembly when the sleeveassembly is disposed subjacent the window. In some embodiments, at leasta portion of a distal end of the piston is adapted to be disposed withinthe drug container when the piston is disposed in the retracted firstposition and the drug pump drive mechanism is disposed for use incooperation with the drug container.

At least some embodiments of the present invention provide the necessarydrive force to push a plunger seal and a drug fluid within a drugcontainer, while reducing or minimizing the drive mechanism and overalldevice footprint. Accordingly, the present invention may provide a drivemechanism which may be utilized within a more compact drug delivery pumpdevice. Some embodiments of the present invention may similarly beutilized to provide additional force, as may be needed for highlyviscous drug fluids or for larger volume drug containers.

According to another aspect of the disclosure, there is provided a drugpump drive mechanism for use in cooperation with a drug containerincluding a plunger seal and a power and control system. The drivemechanism includes a drive housing, a piston, at least one biasingmember, a retainer, sleeve assembly, and an end-of-dose indicator. Thedrive housing includes an axis, the housing further includes at leastone window. The piston is disposed for movement from at least aretracted first position to an extended second position along the axis.The piston is also adapted to impart movement to the plunger seal withinthe drug container. The at least one biasing member is disposed andadapted to move from an energized first position to a deenergized secondposition as a result of the release of energy. The biasing member isalso disposed to cause movement of the piston from the retracted firstposition to the extended second position as the biasing member movesfrom the energized first position to the deenergized second position.The retainer is moveable between a retaining first position and areleasing second position. The retainer is disposed to maintain thebiasing member in the energized first position when the retainer is inthe retaining first position, and to release the biasing member from thefirst energized position when the retainer moves to the releasing secondposition. The sleeve assembly is disposed at least partially within thedrive housing. At least a portion of the sleeve assembly is adapted tomove along the axis with the piston. At least a portion of the sleeveassembly being visible through the window when the piston is one of theretracted first position or the extended second position, the sleeveassembly is not visible through the window when the piston is in theother of the retracted first position or the extended second position.The end-of-dose indicator includes at least one switch interconnect, atleast a portion of which is disposed substantially adjacent the windowand adapted to identify at least one of when the sleeve assembly isdisposed subjacent the window and when the sleeve assembly is notdisposed subjacent the window. The switch interconnect includes amechanical trigger adapted to engage the sleeve assembly through thewindow. The switch interconnect is further adapted to selectively engagethe power and control system as a result of the engagement ordisengagement end of the trigger.

The novel embodiments of the present invention provide drive mechanismswith integrated status indication, which are capable of provideincremental status of the drug delivery before, during, and afteroperation of the device, and provides means for ensuring drug dosecompliance, i.e., ensuring substantially the entire drug dose has beendelivered to the user. Throughout this specification, unless otherwiseindicated, “comprise,” “comprises,” and “comprising,” or related termssuch as “includes” or “consists of,” are used inclusively rather thanexclusively, so that a stated integer or group of integers may includeone or more other non-stated integers or groups of integers. As will bedescribed further below, the embodiments of the present invention mayinclude one or more additional components which may be consideredstandard components in the industry of medical devices. The components,and the embodiments containing such components, are within thecontemplation of the present invention and are to be understood asfalling within the breadth and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The following non-limiting embodiments of the invention are describedherein with reference to the following drawings, wherein:

FIG. 1A shows an isometric view of a drug delivery pump having safetyintegrated insertion mechanisms, according to one embodiment of thepresent invention;

FIG. 1B shows an isometric view of the interior components of the drugdelivery pump shown in FIG. 1A;

FIG. 1C shows an isometric view of the bottom of the drug delivery pumpshown in FIG. 1A;

FIG. 2 shows an isometric view of a drive mechanism, according to atleast one embodiment of the present invention;

FIG. 3 shows an exploded view, along an axis “A,” of the drive mechanismshown in FIG. 2,

FIG. 4A shows a cross-sectional view of the drive mechanism shown inFIG. 2 in an initial inactive state;

FIG. 4B shows a cross-sectional view of the drive mechanism shown inFIG. 2 in an actuated state;

FIG. 4C shows a cross-sectional view of the drive mechanism shown inFIG. 2 in a further actuated state as drug delivery from the mechanismcontinues;

FIG. 4D shows a cross-sectional view of the drive mechanism shown inFIG. 2 as the mechanism nears completion of drug delivery;

FIG. 4E shows a cross-sectional view of the drive mechanism shown inFIG. 2 as the mechanism performs a compliance push to ensure completionof drug delivery;

FIG. 5 shows an isometric view of a drive mechanism, according to asecond embodiment of the present invention;

FIG. 6 shows an exploded view, along an axis “A,” of the drive mechanismshown in FIG. 5;

FIG. 7 shows a cross-sectional view of the drive mechanism shown in FIG.5 in an actuated state;

FIG. 8 shows an isometric view of the drive mechanism according to afurther embodiment of the present invention;

FIG. 9A shows a cross-sectional view of the drive mechanism shown inFIG. 8 in an initial inactive state;

FIG. 9B shows a cross-sectional view of the drive mechanism shown inFIG. 8 in an actuated state and as the mechanism nears completion ofdrug delivery;

FIG. 9C shows a cross-sectional view of the drive mechanism shown inFIG. 8 as the mechanism completes drug delivery and triggers anend-of-dose signal.

FIG. 10A is an isometric view of yet another embodiment of a drugdelivery pump having safety integrated insertion mechanisms inaccordance with teachings of the present invention;

FIG. 10B is an isometric view of the interior components of the drugdelivery pump shown in FIG. 10A;

FIG. 10C is an isometric view of the bottom of the drug delivery pumpshown in FIG. 10A;

FIG. 11 is an isometric view of a drive mechanism, according to at theembodiment of FIGS. 10A-10C;

FIG. 12 is an exploded view, along an axis “A,” of the drive mechanismshown in FIG. 11,

FIG. 13A is a cross-sectional view of the drive mechanism shown in FIG.11 in an initial inactive state;

FIG. 13B is a cross-sectional view of the drive mechanism shown in FIG.11 in an actuated state;

FIG. 13C is a cross-sectional view of the drive mechanism shown in FIG.11 at the completion of drug delivery;

FIG. 14A is a cross-sectional view of the drive mechanism taken alongline 14-14 in FIG. 11;

FIG. 14B is a cross-sectional view of the drive mechanism similar toFIG. 14A, but after the activation of the sensor;

FIG. 15 is an isometric view of a drive mechanism, according to yetanother embodiment of the present invention;

FIG. 16A is a cross-sectional view of the drive mechanism taken alongline 15-15 in FIG. 15; and

FIG. 16B is a cross-sectional view of the drive mechanism similar toFIG. 16A, but after the activation of the sensor.

DETAILED DESCRIPTION

As used herein to describe the drive mechanisms, drug delivery pumps, orany of the relative positions of the components of the presentinvention, the terms “axial” or “axially” refer generally to alongitudinal axis “A” around which the drive mechanisms are preferablypositioned, although not necessarily symmetrically there-around. Theterm “radial” refers generally to a direction normal to axis A. Theterms “proximal,” “rear,” “rearward,” “back,” or “backward” refergenerally to an axial direction in the direction “P”. The terms“distal,” “front,” “frontward,” “depressed,” or “forward” refergenerally to an axial direction in the direction “D”. As used herein,the term “glass” should be understood to include other similarlynon-reactive materials suitable for use in a pharmaceutical gradeapplication that would normally require glass, including but not limitedto certain non-reactive polymers such as cyclic olefin copolymers (COC)and cyclic olefin polymers (COP). The term “plastic” may include boththermoplastic and thermosetting polymers. Thermoplastic polymers can bere-softened to their original condition by heat; thermosetting polymerscannot. As used herein, the term “plastic” refers primarily to moldablethermoplastic polymers such as, for example, polyethylene andpolypropylene, or an acrylic resin, that also typically contain otheringredients such as curatives, fillers, reinforcing agents, colorants,and/or plasticizers, etc., and that can be formed or molded under heatand pressure. As used herein, the term “plastic” is not meant to includeglass, non-reactive polymers, or elastomers that are approved for use inapplications where they are in direct contact with therapeutic liquidsthat can interact with plastic or that can be degraded by substituentsthat could otherwise enter the liquid from plastic. The term“elastomer,” “elastomeric” or “elastomeric material” refers primarily tocross-linked thermosetting rubbery polymers that are more easilydeformable than plastics but that are approved for use withpharmaceutical grade fluids and are not readily susceptible to leachingor gas migration under ambient temperature and pressure. “Fluid” refersprimarily to liquids, but can also include suspensions of solidsdispersed in liquids, and gasses dissolved in or otherwise presenttogether within liquids inside the fluid-containing portions ofsyringes. According to various aspects and embodiments described herein,reference is made to a “biasing member”, such as in the context of oneor more biasing members for insertion or retraction of the needle,trocar, and/or cannula. It will be appreciated that the biasing membermay be any member that is capable of storing and releasing energy.Non-limiting examples include a spring, such as for example a coiledspring, a compression or extension spring, a torsional spring, and aleaf spring, a resiliently compressible or elastic band, or any othermember with similar functions. In at least one embodiment of the presentinvention, the biasing member is a spring, preferably a compressionspring.

The novel devices of the present invention provide drive mechanisms withintegrated status indication and drug delivery pumps which incorporatesuch drive mechanisms. Such devices are safe and easy to use, and areaesthetically and ergonomically appealing for self-administeringpatients. The devices described herein incorporate features which makeactivation, operation, and lock-out of the device simple for evenuntrained users. The novel devices of the present invention providethese desirable features without any of the problems associated withknown prior art devices. Certain non-limiting embodiments of the noveldrug delivery pumps, drive mechanisms, and their respective componentsare described further herein with reference to the accompanying figures.

As used herein, the term “pump” is intended to include any number ofdrug delivery systems which are capable of dispensing a fluid to a userupon activation. Such drug delivery systems include, for example,injection systems, infusion pumps, bolus injectors, and the like. FIGS.1A-1C show an exemplary drug delivery device according to at least oneembodiment of the present invention. The drug delivery device may beutilized to administer delivery of a drug treatment into a body of auser. As shown in FIGS. 1A-1C, the drug pump 10 includes a pump housing12. Pump housing 12 may include one or more housing subcomponents whichare fixedly engageable to facilitate easier manufacturing, assembly, andoperation of the drug pump. For example, drug pump 10 includes a pumphousing 12 which includes an upper housing 12A and a lower housing 12B.The drug pump may further include an activation mechanism 14, a statusindicator 16, and a window 18. Window 18 may be any translucent ortransmissive surface through which the operation of the drug pump may beviewed. As shown in FIG. 1B, drug pump further includes assemblyplatform 20, sterile fluid conduit 30, drive mechanism 100 having drugcontainer 50, insertion mechanism 200, fluid pathway connection 300, andpower and control system 400. One or more of the components of such drugpumps may be modular in that they may be, for example, pre-assembled asseparate components and configured into position onto the assemblyplatform 20 of the drug pump 10 during manufacturing.

The pump housing 12 contains all of the device components and provides ameans of removably attaching the device 10 to the skin of the user. Thepump housing 12 also provides protection to the interior components ofthe device 10 against environmental influences. The pump housing 12 isergonomically and aesthetically designed in size, shape, and relatedfeatures to facilitate easy packaging, storage, handling, and use byusers who may be untrained and/or physically impaired. Furthermore, theexternal surface of the pump housing 12 may be utilized to provideproduct labeling, safety instructions, and the like. Additionally, asdescribed above, housing 12 may include certain components, such asstatus indicator 16 and window 18, which may provide operation feedbackto the user.

In at least one embodiment, the drug pump 10 provides an activationmechanism 14 that is displaced by the user to trigger the start commandto the power and control system 400. In a preferred embodiment, theactivation mechanism is a start button 14 that is located through thepump housing 12, such as through an aperture between upper housing 12Aand lower housing 12B, and which contacts a control arm 40 of the powerand control system 400. In at least one embodiment, the start button 14may be a push button, and in other embodiments, may be an on/off switch,a toggle, or any similar activation feature known in the art. The pumphousing 12 also provides a status indicator 16 and a window 18. In otherembodiments, one or more of the activation mechanism 14, the statusindicator 16, the window 18, and combinations thereof may be provided onthe upper housing 12A or the lower housing 12B such as, for example, ona side visible to the user when the drug pump 10 is placed on the bodyof the user. Housing 12 is described in further detail hereinafter withreference to other components and embodiments of the present invention.

Drug pump is configured such that, upon activation by a user bydepression of the activation mechanism, the drug pump is initiated to:insert a fluid pathway into the user; enable, connect, or open necessaryconnections between a drug container, a fluid pathway, and a sterilefluid conduit; and force drug fluid stored in the drug container throughthe fluid pathway and fluid conduit for delivery into a user. One ormore optional safety mechanisms may be utilized, for example, to preventpremature activation of the drug pump. For example, an optional on-bodysensor 24 (shown in FIG. 1C) may be provided in one embodiment as asafety feature to ensure that the power and control system 400, or theactivation mechanism, cannot be engaged unless the drug pump 10 is incontact with the body of the user. In one such embodiment, the on-bodysensor 24 is located on the bottom of lower housing 12B where it maycome in contact with the user's body. Upon displacement of the on-bodysensor 24, depression of the activation mechanism is permitted.Accordingly, in at least one embodiment the on-body sensor 24 is amechanical safety mechanism, such as for example a mechanical lock out,that prevents triggering of the drug pump 10 by the activation mechanism14. In another embodiment, the on-body sensor may be anelectro-mechanical sensor such as a mechanical lock out that sends asignal to the power and control system 400 to permit activation. Instill other embodiments, the on-body sensor can be electrically basedsuch as, for example, a capacitive- or impedance-based sensor which mustdetect tissue before permitting activation of the power and controlsystem 400. These concepts are not mutually exclusive and one or morecombinations may be utilized within the breadth of the present inventionto prevent, for example, premature activation of the drug pump. In apreferred embodiment, the drug pump 10 utilizes one or more mechanicalon-body sensors. Additional integrated safety mechanisms are describedherein with reference to other components of the novel drug pumps.

Power and Control System:

The power and control system 400 includes a power source, which providesthe energy for various electrical components within the drug pump, oneor more feedback mechanisms, a microcontroller, a circuit board, one ormore conductive pads, and one or more interconnects. Other componentscommonly used in such electrical systems may also be included, as wouldbe appreciated by one having ordinary skill in the art. The one or morefeedback mechanisms may include, for example, audible alarms such aspiezo alarms and/or light indicators such as light emitting diodes(LEDs). The microcontroller may be, for example, a microprocessor. Thepower and control system 400 controls several device interactions withthe user and interfaces with the drive mechanism 100. In one embodiment,the power and control system 400 interfaces with the control arm 40 toidentify when the on-body sensor 24 and/or the activation mechanism 14have been activated. The power and control system 400 may also interfacewith the status indicator 16 of the pump housing 12, which may be atransmissive or translucent material which permits light transfer, toprovide visual feedback to the user. The power and control system 400interfaces with the drive mechanism 100 through one or moreinterconnects to relay status indication, such as activation, drugdelivery, and end-of-dose, to the user. Such status indication may bepresented to the user via auditory tones, such as through the audiblealarms, and/or via visual indicators, such as through the LEDs. In apreferred embodiment, the control interfaces between the power andcontrol system and the other components of the drug pump are not engagedor connected until activation by the user. This is a desirable safetyfeature that prevents accidental operation of the drug pump and mayadditionally maintain the energy contained in the power source duringstorage, transportation, and the like.

The power and control system 400 may be configured to provide a numberof different status indicators to the user. For example, the power andcontrol system 400 may be configured such that after the on-body sensorand/or trigger mechanism have been pressed, the power and control system400 provides a ready-to-start status signal via the status indicator 16if device start-up checks provide no errors. After providing theready-to-start status signal and, in an embodiment with the optionalon-body sensor, if the on-body sensor remains in contact with the bodyof the user, the power and control system 400 will power the drivemechanism 100 to begin delivery of the drug treatment through the fluidpathway connection 300 and sterile fluid conduit 30. In a preferredembodiment of the present invention, the insertion mechanism 200 and thefluid pathway connection 300 may be caused to activate directly by useroperation of the activation mechanism 14.

During the drug delivery process, the power and control system 400 isconfigured to provide a dispensing status signal via the statusindicator 16. After the drug has been administered into the body of theuser and after the end of any additional dwell time, to ensure thatsubstantially the entire dose has been delivered to the user, the powerand control system 400 may provide an okay-to-remove status signal viathe status indicator 16. This may be independently verified by the userby viewing the drive mechanism and drug dose delivery through the window18 of the pump housing 12. Additionally, the power and control system400 may be configured to provide one or more alert signals via thestatus indicator 16, such as for example alerts indicative of fault oroperation failure situations.

Furthermore, the power and control system 400 may be configured to bereadily removable from the pump housing 12. In at least one embodiment,the power and control system 400, or certain portions thereof, may beremoved from the pump housing 12 by opening a hatch in the pump housing12, disconnecting or detaching the power and control system 400 orportions thereof, and removing the power and control system 400 orportions thereof from the drug pump 10. This may be a desired featurefor drug pumps 10 that are required to meet regulations related to themanufacture, transport, use, and disposal of medical devices whichcontain electronic components. In such configurations of the power andcontrol system 400 and pump housing 12, certain or all electroniccomponents such as, for example, the PCB board and batteries, may bereadily removed from the drug pump 10 and disposed of by appropriatemethods apart from the other components of the drug pump 10. The drugpumps 10 of the present invention contemplate a latch on the upperhousing 12A of the pump housing 12 for such a purpose, but a number ofother configurations could readily be employed as would be appreciatedby one having ordinary skill in the art.

Other power and control system configurations may be utilized with thenovel drug pumps of the present invention. For example, certainactivation delays may be utilized during drug delivery. As mentionedabove, one such delay optionally included within the systemconfiguration is a dwell time which ensures that substantially theentire drug dose has been delivered before signaling completion to theuser. Similarly, activation of the device may require a delayeddepression (i.e., pushing) of the activation mechanism 14 of the drugpump 10 prior to drug pump activation. Additionally, the system mayinclude a feature which permits the user to respond to the end-of-dosesignals and to deactivate or power-down the drug pump. Such a featuremay similarly require a delayed depression of the activation mechanism,to prevent accidental deactivation of the device. Such features providedesirable safety integration and ease-of-use parameters to the drugpumps. An additional safety feature may be integrated into theactivation mechanism to prevent partial depression and, therefore,partial activation of the drug pumps. For example, the activationmechanism and/or power and control system may be configured such thatthe device is either completely off or completely on, to prevent partialactivation. Such features are described in further detail hereinafterwith regard to other aspects of the novel drug pumps.

Fluid Pathway Connection:

The fluid pathway connection 300 includes a sterile fluid conduit 30, apiercing member, a connection hub, and a sterile sleeve. The fluidpathway connection may further include one or more flow restrictors.Upon proper activation of the device 10, the fluid pathway connection300 is enabled to connect the sterile fluid conduit 30 to the drugcontainer of the drive mechanism 100. Such connection may be facilitatedby a piercing member, such as a needle, penetrating a pierceable seal ofthe drug container of the drive mechanism 100. The sterility of thisconnection may be maintained by performing the connection within aflexible sterile sleeve. Upon substantially simultaneous activation ofthe insertion mechanism, the fluid pathway between drug container andinsertion mechanism is complete to permit drug delivery into the body ofthe user.

In at least one embodiment of the present invention, the piercing memberof the fluid pathway connection is caused to penetrate the pierceableseal of the drug container of the drive mechanism by direct action ofthe user, such as by depression of the activation mechanism by the user.For example, the activation mechanism itself may bear on the fluidpathway connection such that displacement of the activation mechanismfrom its original position also causes displacement of the fluid pathwayconnection. In a preferred embodiment, this connection is enabled by theuser depressing the activation mechanism and, thereby, driving thepiercing member through the pierceable seal, because this prevents fluidflow from the drug container until desired by the user. In such anembodiment, a compressible sterile sleeve may be fixedly attachedbetween the cap of the drug container and the connection hub of thefluid pathway connection. The piercing member may reside within thesterile sleeve until a connection between the fluid connection pathwayand the drug container is desired. The sterile sleeve may be sterilizedto ensure the sterility of the piercing member and the fluid pathwayprior to activation.

The drug pump is capable of delivering a range of drugs with differentviscosities and volumes. The drug pump is capable of delivering a drugat a controlled flow rate (speed) and/or of a specified volume. In oneembodiment, the drug delivery process is controlled by one or more flowrestrictors within the fluid pathway connection and/or the sterile fluidconduit. In other embodiments, other flow rates may be provided byvarying the geometry of the fluid flow path or delivery conduit, varyingthe speed at which a component of the drive mechanism advances into thedrug container to dispense the drug therein, or combinations thereof.Still further details about the fluid pathway connection 300 and thesterile fluid conduit 30 are provided hereinafter in later sections inreference to other embodiments.

Insertion Mechanism:

A number of insertion mechanisms may be utilized within the drug pumpsof the present invention. In at least one embodiment, the insertionmechanism 200 includes an insertion mechanism housing having one or morelockout windows, and a base for connection to the assembly platformand/or pump housing (as shown in FIG. 1B and FIG. 1C). The connection ofthe base to the assembly platform 20 may be, for example, such that thebottom of the base is permitted to pass-through a hole in the assemblyplatform to permit direct contact of the base to the body of the user.In such configurations, the bottom of the base may include a sealingmembrane that is removable prior to use of the drug pump 10. Theinsertion mechanism may further include one or more insertion biasingmembers, a needle, a retraction biasing member, a cannula, and amanifold. The manifold may connect to sterile fluid conduit 30 to permitfluid flow through the manifold, cannula, and into the body of the userduring drug delivery.

As used herein, “needle” is intended to refer to a variety of needlesincluding but not limited to conventional hollow needles, such as arigid hollow steel needles, and solid core needles more commonlyreferred to as a “trocars.” In a preferred embodiment, the needle is a27 gauge solid core trocar and in other embodiments, the needle may beany size needle suitable to insert the cannula for the type of drug anddrug administration (e.g., subcutaneous, intramuscular, intradermal,etc.) intended. A sterile boot may be utilized within the needleinsertion mechanism. The sterile boot is a collapsible sterile membranethat is in fixed engagement at a proximal end with the manifold and at adistal end with the base. In at least on embodiment, the sterile boot ismaintained in fixed engagement at a distal end between base andinsertion mechanism housing. Base includes a base opening through whichthe needle and cannula may pass-through during operation of theinsertion mechanism, as will be described further below. Sterility ofthe cannula and needle are maintained by their initial positioningwithin the sterile portions of the insertion mechanism. Specifically, asdescribed above, needle and cannula are maintained in the sterileenvironment of the manifold and sterile boot. The base opening of basemay be closed from non-sterile environments as well, such as by forexample a sealing membrane 254 (shown in FIG. 1C).

According to at least one embodiment of the present invention, theinsertion mechanism is initially locked into a ready-to use-stage bylockout pin(s) which are initially positioned within lockout windows ofthe insertion mechanism housing. In this initial configuration,insertion biasing member and retraction biasing member are each retainedin their compressed, energized states. As shown in FIG. 1B, the lockoutpin(s) 208 may be directly displaced by user depression of theactivation mechanism 14. As the user disengages any safety mechanisms,such as an optional on-body sensor 24 (shown in FIG. 1C), the activationmechanism 14 may be depressed to initiate the drug pump. Depression ofthe activation mechanism 14 may directly cause translation ordisplacement of control arm 40 and directly or indirectly causedisplacement of lockout pin(s) 208 from their initial position withinlocking windows 202A of insertion mechanism housing 202. Displacement ofthe lockout pin(s) 208 permits insertion biasing member to decompressfrom its initial compressed, energized state. This decompression of theinsertion biasing member drives the needle and the cannula into the bodyof the user. At the end of the insertion stage, the retraction biasingmember is permitted to expand in the proximal direction from its initialenergized state. This axial expansion in the proximal direction of theretraction biasing member retracts the needle, while maintaining thecannula in fluid communication with the body of the user. Accordingly,the insertion mechanism may be used to insert a needle and cannula intothe user and, subsequently, retract the needle while retaining thecannula in position for drug delivery to the body of the user.

Drive Mechanism:

With reference to the embodiments shown in FIGS. 2 and 3, drivemechanism 100 includes a drive housing 130, a status switch interconnect132, and a drug container 50 having a cap 52, a pierceable seal 56, abarrel 58, and a plunger seal 60. The drug container may contain a drugfluid, within the barrel between the pierceable seal and the plungerseal, for delivery through the insertion mechanism and drug pump intothe body of the user. The seals described herein may be comprised of anumber of materials but are, in a preferred embodiment, comprised of oneor more elastomers or rubbers. The drive mechanism may further include aconnection mount 54 to guide the insertion of the piercing member of thefluid pathway connection into the barrel 58 of the drug container 50.The drive mechanism 100 may further contain one or more drive biasingmembers, one or more release mechanisms, and one or more guides, as aredescribed further herein. The components of the drive mechanism functionto force a fluid from the drug container out through the pierceableseal, or preferably through the piercing member of the fluid pathwayconnection, for delivery through the fluid pathway connection, sterilefluid conduit, and insertion mechanism into the body of the user.

The drive mechanism may further include one or more contact surfaceslocated on corresponding components. Such contact surfaces may beelectrical contact surfaces, mechanical contact surfaces, orelectro-mechanical contact surfaces. Such surfaces may initially be incontact and caused to disengage, or initially be disconnected and causedto engage, to permit a signal to be sent to and/or from the powercontrol system 400. In at least one embodiment, as described furtherherein, the contact surfaces may be electrical contact surfaces whichare initially disconnected and caused to come into engagement whereby,upon such engagement, contact surfaces are capable of continuing anenergy pathway or otherwise relaying a signal to the power and controlsystem 400. In another embodiment of the present invention, the contactsurfaces are mechanical contact surfaces which are initially in contactand caused to disengage whereby, upon such disengagement, suchdisengagement is communicated to the power and control system 400. Suchsignals may be transferred across one or more interconnects 132 to thepower and control system 400 or by mechanical action to the power andcontrol system 400. Such components may be utilized within the drivemechanism to measure and relay information related to the status ofoperation of the drive mechanism, which may be converted by the powerand control system 400 into tactile, auditory, and/or visual feedback tothe user. Such embodiments are described further herein. Regardless ofthe electrical or mechanical nature of the contact surfaces, the motionof the components which permits transmission of a signal to the powercontrol system 400 is enabled by a biasing member 122 axiallytranslating a contact sleeve 140 in the distal direction duringoperation of the device.

In one particular embodiment, the drive mechanism 100 employs one ormore compression springs as the biasing member(s). Upon activation ofthe drug pump by the user, the power and control system may be actuatedto directly or indirectly release the compression spring(s) from anenergized state. Upon release, the compression spring(s) may bearagainst and act upon the plunger seal to force the fluid drug out of thedrug container. The fluid pathway connection may be connected throughthe pierceable seal prior to, concurrently with, or after activation ofthe drive mechanism to permit fluid flow from the drug container,through the fluid pathway connection, sterile fluid conduit, andinsertion mechanism, and into the body of the user for drug delivery. Inat least one embodiment, the fluid flows through only a manifold and acannula of the insertion mechanism, thereby maintaining the sterility ofthe fluid pathway before and during drug delivery. Such components andtheir functions are described in further detail hereinafter.

Referring now to the embodiment of the drive mechanism shown in FIG. 3,the drive mechanism 100 includes a drug container 50 having a cap 52, apierceable seal 56, a barrel 58, and a plunger seal 60, and optionally aconnection mount 54. The drug container 50 is mounted to a distal end ofa drive housing 130. Compressed within the drive housing 130, betweenthe drug container 50 and the proximal end of the housing 130, are adrive biasing member 122 and a piston 110, wherein the drive biasingmember 122 is configured to bear upon an interface surface 110C of thepiston 110, as described further herein. Optionally, a cover sleeve 120may be utilized between the drive biasing member 122 and the interfacesurface 110C of the piston 110 to, for example, promote more evendistribution of force from the drive biasing member 122 to the piston110, prevent buckling of the drive biasing member 122, and/or hidebiasing member from user view. Interface surface 110C of piston 110 iscaused to rest substantially adjacent to, or in contact with, a proximalend of seal 60.

The drive mechanism 100 further includes, mounted at a distal end, astatus switch interconnect 132. A contact sleeve 140 is slidably mountedto the drive housing 130 through an axial aperture of the housing 130,such that sleeve hooks 140B at a distal end of the contact sleeve 140are caused to contact the piston 110 between interface surface 110 and acontact protrusion 110B near the proximal end of the piston 110. Piston110 also includes a locking groove 110A, between contact protrusion 110Band the proximal end of the piston 110. Contact sleeve 140 has aradially extending ring 140C at its proximal end, upon which resides oneor more flex prongs 140A. An electrical contact 134 may be connected,mounted, printed, or otherwise mounted to ring 140C which, duringoperation of the drive mechanism, may come in contact with correspondingstatus switch interconnect 132 to complete an electrical circuit orotherwise permit a transmission to the power and control system toprovide feedback to the user.

The components of the drive mechanism 100, upon activation, may be usedto drive axial translation in the distal direction of the plunger seal60 of the drug container 50. Optionally, the drive mechanism 100 mayinclude one or more compliance features which enable additional axialtranslation of the plunger seal 60 to, for example, ensure thatsubstantially the entire drug dose has been delivered to the user andmake sure that the feedback contact mechanisms have connected. Forexample, in one embodiment of the present invention, the sleeve hooks140B are flex arms which may permit, upon sufficient application offorce by the drive biasing member 122 on the piston 110, to allowinterface surface 110C to translate axially beyond sleeve hooks 140B todrive further axial translation of the plunger seal 60 for a compliancepush of drug fluid from the drug container. Additionally oralternatively, the plunger seal 60, itself, may have somecompressibility permitting a compliance push of drug fluid from the drugcontainer.

In at least one embodiment of the present invention, a compliance pushof drug fluid from the drug container is enabled by a piston extension102. In such embodiments, the drive mechanism 100 further includes apiston extension 102 slidably mounted at a distal end and within anaxial pass-through of piston 110. The piston extension 102 may beretained within piston 110 by interaction between extension arms 102B ofthe piston extension 102 and connection slots 110D of piston 110, asshown in FIGS. 4A-4E. Piston extension may be driven by a pistonextension biasing member 106, which is mounted within the axialpass-through of piston 110 and initially compressed between pistonextension 102 and piston 110. An optional piston biasing member support104 may be utilized between piston extension biasing member 106 andpiston extension 102 to, for example, promote more uniform distributionof force from piston extension biasing member 106 to piston extension102. The function of the optional piston extension is described infurther detail hereinafter.

The novel drive mechanisms of the present invention integrate statusindication into the drug dose delivery. By use of one or more statusswitch interconnects and one or more corresponding electrical contacts,the status of the drive mechanism before, during, and after operationcan be relayed to the power and control system to provide feedback tothe user. Such feedback may be tactile, visual, and/or auditory, asdescribed above, and may be redundant such that more than one signals ortypes of feedback are provided to the user during use of the device. Forexample, the user may be provided an initial feedback to identify thatthe system is operational and ready for drug delivery. Upon activation,the system may then provide one or more drug delivery status indicationsto the user. At completion of drug delivery, the drive mechanism anddrug pump may provide an end-of-dose indication. As the end-of-doseindication is tied to the piston reaching the end of its axialtranslation, the drive mechanism and drug pump provide a trueend-of-dose indication to the user.

In at least one embodiment, as shown in FIG. 2 and FIG. 3, anend-of-dose status indication may be provided to the user once thestatus switch interconnect 132 is caused to contact electrical contact134 at the end of axial travel of the piston 110 and plunger 60 withinthe barrel 58 of the drug container 50. In a further embodiment,incremental status indication relaying various stages of drug deliverycan be communicated to the user during operation. In one suchembodiment, sleeve hooks 140B of cover sleeve 120 may have one or moreinterconnects which come into contact with one or more electricalcontacts on the outer surface of piston 110 during operation. As piston110 translates axially in the distal direction to push plunger seal 60distally, thereby pushing fluid out of the drug container through thepierceable seal end, the electrical contacts of the piston 110 maysequentially contact the interconnect on the sleeve hooks 140B to relaythe incremental status of operation. Depending on the number ofelectrical contacts located on the outer surface of the piston 110, thefrequency of the incremental status indication may be varied as desired.The location of the contacts and interconnects may be interchanged or ina number of other configurations which permit completion of anelectrical circuit or otherwise permit a transmission between thecomponents.

In another embodiment of the drive mechanism 500, shown in FIGS. 5 and6, incremental status indication may be measured and relayed by aseparate incremental status stem 650 and a corresponding steminterconnect 652. The stem interconnect 652 may be mounted, affixed,printed, or otherwise attached to incremental status stem 650.Incremental status stem 650 may be a static component, i.e., it does notmove or translate, that is mounted to the distal end of contact sleeve640 and/or the distal end of drive housing 630 such that the incrementalstatus stem 650 resides within an axial pass-through of contact sleeve640 and drive housing 630. The incremental status stem 650 furtherresides within an axial pass-through of piston 610. In such embodimentsof the present invention, one or more contacts may be located on aninner surface of the piston 610 such that they sequentially interfacewith one or more corresponding interconnects on the incremental statusstem 650. As piston 610 translates axially in the distal direction topush plunger seal 60 distally, thereby pushing fluid out of the drugcontainer through the pierceable seal end, the electrical contacts ofthe piston 610 may sequentially contact the interconnect on theincremental status stem 650 to relay the incremental status ofoperation. Depending on the number of electrical contacts, the frequencyof the incremental status indication may be varied as desired. Thelocation of the contacts and interconnects may be interchanged or in anumber of other configurations which permit completion of an electricalcircuit or otherwise permit a transmission between the components.

FIG. 7 shows a cross-sectional view of the embodiment of the drivemechanism shown in FIG. 5 during operation of the drive mechanism. Asshown, incremental status stem 650 may be a static component that ismounted to the distal end of contact sleeve 640 and/or the distal end ofdrive housing 630 such that the incremental status stem 650 resideswithin an axial pass-through of contact sleeve 640 and drive housing630. As piston 610 translates axially in the distal direction (i.e., inthe direction of the solid arrow) to push plunger seal 60 distally, theelectrical contacts of the piston 610 may sequentially contact theinterconnect on the incremental status stem 650 to relay the incrementalstatus of operation through stem interconnect 652. Accordingly,incremental status of the drive mechanism, and therefore status of drugdelivery, may be conveyed to the user during use of the device.

Returning now to the embodiment shown in FIGS. 2-3, further aspects ofthe novel drive mechanism will be described with reference to FIGS.4A-4E. One or more of these aspects may similarly be utilized in theembodiment shown in FIG. 5, or any other variation captured by theembodiments described herein. FIG. 4A shows a cross-sectional view ofthe drive mechanism, according to at least a first embodiment, duringits initial locked stage. A fluid, such as a drug fluid, may becontained within barrel 58, between plunger seal 60 and pierceable seal56, for delivery to a user. Upon activation by the user, a fluid pathwayconnection may be connected to the drug container through the pierceableseal 56. As described above, this fluid connection may be facilitated bya piercing member of the fluid pathway connection which pierces thepierceable seal and completes the fluid pathway from the drug container,through the fluid pathway connection, the fluid conduit, the insertionmechanism, and the cannula for delivery of the drug fluid to the body ofthe user. Initially, one or more locking mechanisms (not shown) mayreside within the locking grooves 110A of piston 110. Directly orindirectly upon activation of the device by the user, the lockingmechanism may be removed from the locking grooves 110A of piston 110, topermit operation of the drive mechanism.

As shown in FIG. 4A, the piston extension biasing member 106 and drivebiasing member 122 are both initially in a compressed, energized state.The drive biasing member 122 may be maintained in this state untilactivation of the device between internal features of drive housing 130and interface surface 110C of piston 110. As the locking mechanism isremoved from the locking groove 110A of piston 110, drive biasing member122 is permitted to expand (i.e., decompress) axially in the distaldirection (i.e., in the direction of the solid arrow). Such expansioncauses the drive biasing member 122 to act upon and distally translateinterface surface 110C and piston 110, thereby distally translatingplunger 60 to push drug fluid out of the barrel 58. Distal translationof the piston 110 causes distal translation of the piston extensionbiasing member 106 and piston extension 102, when such optional featuresare incorporated into the device. As shown in FIG. 4B, such distaltranslation of the piston 110 and plunger seal 60 continues to forcefluid flow out from barrel 58 through pierceable seal 56. Status switchinterconnect 132 is prevented from prematurely contacting electricalcontact 134 by one or more flex prongs 140A, as shown in FIG. 4C.Alternatively, low force springs or other resistance mechanisms may beutilized in addition to or alternatively from flex prongs 140A toachieve the same functions. During distal translation of the piston 110,sleeve hooks 140B may slidably contact the outer surface of piston 110.As described above, interconnects and electrical contacts may be locatedon these components to provide incremental status indication duringoperation of the drive mechanism.

As the drive mechanism 100 nears or reaches end-of-dose, flex prongs140A may be caused to flex outwards (i.e., in the direction of thehollow arrows) by the decompression force of drive biasing member 122.Such flexion of the flex prongs 140A may permit status switchinterconnect 132 to contact electrical contact 134, completing a circuitor otherwise permitting a transmission to the power and control systemto provide feedback to the user. At this stage, one or more deliverycompliance mechanisms may be utilized to ensure that the status switchinterconnect 132 has contacted electrical contact 134 and/or thatsubstantially the entire drug dose has been delivered. For example, inone embodiment of the present invention, the sleeve hooks 140B are flexarms which may permit, upon sufficient application of force by the drivebiasing member 122 on the piston 110, to allow interface surface 110C totranslate axially beyond sleeve hooks 140B to drive further axialtranslation of the plunger seal 60 for a compliance push of drug fluidfrom the drug container. Additionally or alternatively, the plunger seal60, itself, may have some compressibility permitting a compliance pushof drug fluid from the drug container. For example, when a pop-outplunger seal is employed, i.e., a plunger seal that is deformable froman initial state, the plunger seal may be caused to deform or “pop-out”to provide a compliance push of drug fluid from the drug container.

In at least one embodiment of the present invention, a compliance pushof drug fluid from the drug container is enabled by a piston extension102. In such embodiments, the drive mechanism 100 further includes apiston extension 102 slidably mounted at a distal end and within anaxial pass-through of piston 110. The piston extension 102 may beretained within piston 110 by interaction between extension arms 102B ofthe piston extension 102 and connection slots 110D of piston 110, asshown in FIG. 4D. Piston extension may be driven by a piston extensionbiasing member 106, which is mounted within the axial pass-through ofpiston 110 and initially compressed between piston extension 102 andpiston 110. An optional piston biasing member support 104 may beutilized between piston extension biasing member 106 and pistonextension 102 to, for example, promote more uniform distribution offorce from piston extension biasing member 106 to piston extension 102.

As the piston 110 reaches its end of travel within barrel 58, pistonextension 102 may be permitted to axially travel in the distal directionby the force exerted by piston extension biasing member 106. At thisstage, the piston extension biasing member 106 is permitted to expand(i.e., decompress) axially in the distal direction such that extensionarms 102B of the piston extension 102 may translate distally (i.e., inthe direction of the solid arrow) within connection slots 110D of piston110, as shown in FIG. 4D. As shown in FIG. 4E, such distal translation(i.e., in the direction of the hatched arrow) of the piston extension102 enables a compliance push (shown by dimension “C” in FIG. 4E) ofdrug fluid from the drug container. Piston extension 102 may beconfigured such that extension arms 102B may contact and apply forceupon a distal end of connections slots 110D to distally translate piston110 further (i.e., in the direction of the hatched arrow). This furtherdistal translation of the piston 110 may be utilized to ensure thatstatus switch interconnect 132 has engaged contact 134.

As described above, the novel drive mechanisms of the present inventionintegrate status indication into the drug dose delivery. Throughintegration of the end-of-dose status indication mechanisms to the axialtranslation of the piston, and thereby the plunger seal, true andaccurate end-of-dose indication may be provided to the user. By use ofone or more contact surfaces on corresponding components, the status ofthe drive mechanism before, during, and after operation can be relayedto the power and control system to provide feedback to the user. Suchfeedback may be tactile, visual, and/or auditory, as described above,and may be redundant such that more than one signals or types offeedback are provided to the user during use of the device. FIGS. 4A-4Eabove show an arrangement which provide end-of-dose status indication tothe user once the status switch interconnect 132 is caused to contactelectrical contact 134 at the end of axial travel of the piston 110 andplunger 60 within the barrel 58 of the drug container 50. As describedabove, the novel devices described herein may additionally provideincremental status indication to relay various stages of drug deliveryto the user during operation. In one such embodiment, sleeve hooks 140Bof cover sleeve 120 may have one or more interconnects which come intocontact with one or more electrical contacts on the outer surface ofpiston 110 during operation. A redundant end-of-dose indication may beutilized upon contact between sleeve hooks 140B of contact sleeve 140and contact protrusion 110B of piston 110. Electrical contacts orinterconnects along piston 110 may sequentially contact thecorresponding interconnects or contacts on the sleeve hooks 140B torelay the incremental status of operation. Depending on the number ofelectrical contacts located on the outer surface of the piston 110, thefrequency of the incremental status indication may be varied as desired.The location of the contacts and interconnects may be interchanged or ina number of other configurations which permit completion of anelectrical circuit or otherwise permit a transmission between thecomponents.

In another embodiment of the drive mechanism 500, shown in FIGS. 5-7,incremental status indication may be measured and relayed by a separateincremental status stem 650 and a corresponding stem interconnect 652.As shown in FIG. 7, incremental status stem 650 may be a staticcomponent that is mounted to the distal end of contact sleeve 640 and/orthe distal end of drive housing 630 such that the incremental statusstem 650 resides within an axial pass-through of contact sleeve 640 anddrive housing 630. As piston 610 translates axially in the distaldirection (i.e., in the direction of the solid arrow) to push plungerseal 60 distally, the electrical contacts of the piston 610 maysequentially contact the interconnect on the incremental status stem 650to relay the incremental status of operation through stem interconnect652. Depending on the number of electrical contacts, the frequency ofthe incremental status indication may be varied as desired. The locationof the contacts and interconnects may be interchanged or in a number ofother configurations which permit completion of an electrical circuit orotherwise permit a transmission between the components. Accordingly,incremental status of the drive mechanism, and therefore status of drugdelivery, may be conveyed to the user during use of the device.

In a further embodiment of the drive mechanism, shown in FIGS. 8 and9A-9C, drive mechanism 1000 may be similar to mechanism 100 or mechanism500, and incorporate the respective components and functions of suchembodiments, but utilize mechanical contact surfaces instead ofelectrical contact surfaces, as described above. FIG. 8 shows anisometric view of the drive mechanism 1000 according to a furtherembodiment of the present invention. FIGS. 9A-9C show cross-sectionalviews of the drive mechanism shown in FIG. 8 in an initial inactivestate, an actuated state and as the mechanism nears completion of drugdelivery, and as the mechanism completes drug delivery and triggers anend-of-dose signal. In such embodiments, the status switch interconnectis a mechanical trigger 1150 and the contact surface is a pin 1140P. Asshown in FIG. 9A, the optional piston extension biasing member 1106 anddrive biasing member 1122 are both initially in a compressed, energizedstate. The drive biasing member 1122 may be maintained in this stateuntil activation of the device between internal features of drivehousing 1130 and interface surface 1110C of piston 1110. As the lockingmechanism is removed from the locking groove 1110A of piston 1110, drivebiasing member 1122 is permitted to expand (i.e., decompress) axially inthe distal direction (i.e., in the direction of the solid arrow). Suchexpansion causes the drive biasing member 1122 to act upon and distallytranslate interface surface 1110C and piston 1110, thereby distallytranslating plunger 1060 to push drug fluid out of the barrel 1058.Distal translation of the piston 1110 causes distal translation of thepiston extension biasing member 1106 and piston extension 1102, whensuch optional features are incorporated into the device.

As shown in FIG. 9B, such distal translation of the piston 1110 andplunger seal 1060 continues to force fluid flow out from barrel 1058through pierceable seal 1056. As described above, interconnects andelectrical contacts may be located on these components to provideincremental status indication during operation of the drive mechanism.As shown in FIG. 9C, as the drive mechanism 1000 reaches end-of-dose,pin 1140P disengages from mechanical trigger 1150 to permit atransmission to the power and control system 400 to provide feedback tothe user. In one such embodiment, disengagement of the pin 1140P fromthe mechanical trigger 1150 permits the trigger to rotate as it isbiased by a biasing member, such as a constant-force spring 1170.Initially, the constant-force spring 1170 biases the mechanical trigger1150 against the pin 1140P. Upon axial translation of the pin 1140P, asdescribed above, pin 1140P disengages from mechanical trigger 1150 whichthen rotates or is otherwise displaced to permit transmission offeedback to the user. At this stage, one or more delivery compliancemechanisms, as described above, may be utilized to ensure that the pin1140P has disengaged mechanical trigger 1150 and/or that substantiallythe entire drug dose has been delivered.

Assembly and/or manufacturing of drive mechanism 100, drug delivery pump10, or any of the individual components may utilize a number of knownmaterials and methodologies in the art. For example, a number of knowncleaning fluids such as isopropyl alcohol and hexane may be used toclean the components and/or the devices. A number of known adhesives orglues may similarly be employed in the manufacturing process.Additionally, known siliconization and/or lubrication fluids andprocesses may be employed during the manufacture of the novel componentsand devices. Furthermore, known sterilization processes may be employedat one or more of the manufacturing or assembly stages to ensure thesterility of the final product.

The drive mechanism may be assembled in a number of methodologies. Inone method of assembly, the drug container 50 may first be assembled andfilled with a fluid for delivery to the user. The drug container 50includes a cap 52, a pierceable seal 56, a barrel 58, and a plunger seal60. The pierceable seal 56 may be fixedly engaged between the cap 52 andthe barrel 58, at a distal end of the barrel 58. The barrel 58 may befilled with a drug fluid through the open proximal end prior toinsertion of the plunger seal 60 from the proximal end of the barrel 58.An optional connection mount 54 may be mounted to a distal end of thepierceable seal 56. The connection mount 54 to guide the insertion ofthe piercing member of the fluid pathway connection into the barrel 58of the drug container 50. The drug container 50 may then be mounted to adistal end of drive housing 130.

One or more switch status interconnects 132 may be mounted to a proximalend of drive housing 130. A contact sleeve 140, having one or moresleeve hooks 140B at a distal end and a ring 140C at a proximal endhaving an electrical contact 134 thereon, may be mounted to the drivehousing 130 through an axial pass-through from the proximal end of thedrive housing 130. A drive biasing member 122 may be inserted into adistal end of the drive housing 130. Optionally, a cover sleeve 120 maybe inserted into a distal end of the drive housing 130 to substantiallycover biasing member 122. A piston may be inserted into the distal endof the drive housing 130 and through an axial pass-through of contactsleeve 140, such that a contact protrusion 110B of piston 110 isproximal to the sleeve hooks 140B of contact sleeve 140. The piston 110and drive biasing member 122, and optional cover sleeve 120, may becompressed into drive housing 130. Such assembly positions the drivebiasing member 122 in an initial compressed, energized state andpreferably places a piston interface surface 110C in contact with theproximal surface of the plunger seal 60 within the proximal end ofbarrel 58. When a piston extension 102 is employed, the piston extension102 and piston extension biasing member 106, and optional piston biasingmember support, may be compressed into an axial pass-through of piston110. The piston, piston biasing member, contact sleeve, and optionalcomponents, may be compressed and locked into the ready-to-actuate statewithin the drive housing 130 prior to attachment or mounting of the drugcontainer 50.

When one or more interconnects or contacts are utilized for statusindication, such components may be mounted, connected, printed, orotherwise attached to their corresponding components prior to assemblyof such components into the drive mechanism 100. When a separateincremental status stem 650 and a corresponding stem interconnect 652are utilized for such incremental status indication, the steminterconnect 652 may be mounted, affixed, printed, or otherwise attachedto incremental status stem 650. The incremental status stem 650 and steminterconnect 652 to the proximal end of the contact sleeve 640 and/orthe proximal end of the drive housing 630 in a manner such that theincremental status stem 650 resides within an axial pass-through ofcontact sleeve 640 and drive housing 630. The incremental status stem650 is further mounted to reside within an axial pass-through of piston610.

It will be appreciated that the end-of-dose indicator orinterconnects/contact may include any appropriate arrangement,including, for example, mechanical, electrical, electromechanical,ultrasonic, capacitive or magnetic arrangements. Similarly, the drivemechanism may be of any appropriate design.

Alternate arrangements of both the drive mechanism and end-of-doseindicator or interconnects/contact are illustrated, for example, inFIGS. 10A-14B. For the sake of clarity, the reference numbers utilizedin FIGS. 10A-14B are similar to those of the embodiment of FIGS. 1A-4C,only preceded by the number “2” or “20” as appropriate to provide areference number having four digits, i.e., 2XXX. For example, the drugpump and drive mechanism of FIGS. 10A-14B will be designated by thenumbers 2010 and 2100, respectively, as opposed to the drug pump 10 anddrive mechanism 100 of FIGS. 1A-4E. This correlation, however, shouldnot be taken as an indication that the components of FIGS. 10A-14B withreference numbers similar to those of the embodiment of FIGS. 1A-4E areexactly the same as the respective components of FIGS. 1A-4E.

As shown in FIGS. 10A-10C, the drug pump 2010 includes a drive mechanism2100 for receiving a drug container 2050, an insertion mechanism 2200, afluid pathway connection 2300 including a fluid conduit 2030, and apower and control system 2400, all residing within a housing 2012, andan activation mechanism 2014 actuable by a user from the outside of thehousing 2012. The housing 2012 may take any number of configurations andbe facilitated by any number of components, such as a single-body ormulti-component housing 2012. Certain other components, such aselectronics for power and signaling, activation buttons, and safetysensors are also omitted for clarity, but are understood to be standardcomponents within such drug pump devices. While the housing 2012,insertion mechanism 2200, fluid pathway connection 2300, and power andcontrol system 2500, as well as the activation mechanism 2014 are notdiscussed in detail, those of skill in the art will appreciate that theymay be the same or similar to the components and systems discussed indetail with regard to the other embodiments disclosed herein.

The drive mechanism 2100, primary drug container 2050, and a portion ofthe fluid pathway connection 2300 are shown isometrically in FIG. 11 andexploded form in FIG. 12. FIGS. 13A-13C illustrate the drive mechanism2100 in cross-section as it progresses through several stages ofoperation. FIGS. 14A-14B illustrate a lateral cross-section of the drivemechanism 2100 at several stages of operation.

The primary drug container 2050 retains the drug treatment that is to beinjected or infused into the patient, and may be a vial or similarcontainer from which a drug treatment can be dosed. To provide a sterileenvironment for the drug treatment, the drug container 2050 may includea cylindrical barrel 2058 with a pierceable seal 2056 disposed in adistal end and a plunger seal 2060 disposed within a proximal end. Thepierceable seal 2056 and plunger seal 2060 may be formed of a number ofmaterials, such as one or more elastomeric materials, and are sized andformulated to maintain a seal with the barrel 2058.

The portion of the fluid pathway connection 2300 illustrated in FIGS.11-13C includes a connection mount 2054, a sterile boot 2310, and apiercing assembly 2320. The piercing assembly 2320 includes a piercingmember 2322 extending from a hub 2324 which supports the piercing member2322, and provides a fluid connection 2326 (see FIG. 11) to which thefluid conduit 2030 or other fluid connector may be fluidly coupled tofluidly couple the drug container 2050 to the insertion mechanism 2200.The connection mount 2054 is disposed adjacent the pierceable seal 2056and includes an aperture adapted to guide the insertion of the piercingmember 2322 of the fluid pathway connection into the pierceable seal2056 of the drug container 2050. The sterile boot 2310 is disposed aboutthe piercing assembly 2320 and provides a sterile environment for thecompletion of the fluid coupling of the fluid pathway connection 2300. Acollar 2052 may be provided in order to secure a flange of the sterileboot 2310, the connection mount 2054, the pierceable seal, and thebarrel 2058 in fixed relation to one another.

Referring to FIGS. 1A and 1B, in operation, when a user activates theactivation mechanism 2014, as by depressing the illustrated startbutton, an arm 2015 coupled to the activation mechanism 2014 exerts anaxial force on the piercing assembly 2320 to move the piercing member2322 axially to pierce the pierceable seal 2056. The drive mechanism2100 is adapted for use in cooperation with the proximal end of the drugcontainer 2050 to axially advance the plunger seal 2060 within thebarrel 2058 to dispense the drug treatment through the fluid pathwayconnection 2300 once the pierceable seal 2056 has been pierced by thepiercing member 2322.

The drive mechanism 2100 includes a drive housing 2130 having an axisthat is coincident with the axis A of the drive mechanism 2100 (see FIG.11). The axis A may be disposed in coincident with axes in the container2050 and the plunger seal 2060. A piston 2110 is at least partiallydisposed within the drive housing 2130 for longitudinal movement alongthe axis of the drive mechanism 2100. It will be appreciated that theterm “axis” when used in connection with the drive housing 2130 is notintended to require the axis to be in a central location of the drivehousing 2130 or that the drive housing 2130 be round.

The piston 2110 is mounted to move between a retracted first position(illustrated in FIG. 13A), wherein the piston 2110 is at least partiallydisposed within the drive housing 2130, and an extended second position(illustrated in FIGS. 13B and 13C), wherein the piston 2110 extendsaxially outward from drive housing 2130. The piston 2110 includes aninterface surface 2110C that is disposed to either directly confront theplunger seal 2060 when assembled with a drug container 2050, or tootherwise transmit an actuating force to the plunger seal 2060. In otherwords, the piston 2110 of the drive mechanism 2100 of FIGS. 10A-14B isadapted to exert a dispensing force on the plunger seal 2060 of the drugcontainer 2050 and to translate outward from a distal end of a housing2012 to advance the plunger seal 2060 within the drug container 2050 todispense the drug. While the initial position shown in FIG. 13Aillustrates the interface surface 2110C of the piston 2110 as disposedsubstantially adjacent the distal end of the housing 2012, it will beappreciated that, in alternate embodiments, the piston may be initiallydisposed in a position extending outside of the drive housing 2130. Insuch an arrangement, in initial assembly of the drive mechanism 2100with a drug container 2050, the piston 2110 may be initially at leastpartially disposed within proximal end of the drug container 2050.

In order to impart axial movement to the piston 2010, the drivemechanism 2100 further includes a plurality of piston biasing members2106, 2122 disposed to move from an energized first position when thepiston 2110 is in the retracted first position to a deenergized secondposition when the piston 2110 is in an extended second position. It willbe appreciated that, for the purposes of this disclosure and theaccompanying claims, the term “deenergized second position” is arelative term. That is, the piston biasing members 2106, 2122 in the“deenergized second position” have less energy than the piston biasingmembers 2106, 2122 in the “energized first position.” That is not tosay, however, that the piston biasing members 2106, 2122 in the“deenergized second position” are necessarily completely deenergized orstoring no energy.

So long as the piston 2110 is maintained in the retracted firstposition, biasing members 2106, 2122 are maintained in their energizedfirst position (see FIG. 13A). The piston 2110 is maintained in theretracted first position by a retaining element or clip 2115. While anyappropriate arrangement may be utilized to retain the piston 2110 in theretracted first position, the clip 2115 may bear against an outsidesurface of the drug pump housing 2012 and be received in a lockinggroove 2110A of the piston 2110. FIG. 13A illustrates the clip 2115disposed in such a retaining first position. It will thus be appreciatedby those of skill in the art that the engagement of the retainingelement or clip 2115 to maintain the piston 2110 in its retracted firstposition with the biasing members 2106, 2122 in their energized firstposition, allows the drive mechanism 2100 to be handled as aself-contained unit such that it may be assembled into the drug pump2010 or in cooperation with a drug container 2050. In operation,however, once the clip 2115 is removed or moved to a releasing secondposition (see FIGS. 12B and 13C), the piston biasing members 2106, 2122exert an axial dispensing force on the piston 2110 as they move to adeenergized second position and the piston moves to its extended secondposition. In at least one embodiment, clip 2115 may be removed throughan action caused, directly or indirectly, by movement of the activationmechanism 2014. The action removing clip 2115 can be achieved in anumber of ways. For example, with reference to FIG. 12, the actionremoving clip 2114 is a linear, perpendicular movement relative to theaxis “A” of the drug container 2050.

In accordance with an aspect of the invention as illustrated in theembodiment of FIGS. 10A-31C, the drive mechanism 2100 is small in sizeand/or device footprint, yet capable of providing the dispensing forceneeded to push a drug fluid from a drug container 2050 through a fluidconduit 2030 for drug delivery via an insertion mechanism 2200. In thisembodiment of the drive mechanism 2100, the piston biasing members 2106,2122 are disposed in parallel, in contrast to the series disposal of theembodiments of FIGS. 1A-9C. It will thus be appreciated by those ofskill in the art that the drive mechanism 2100 of FIGS. 10A-14B yields asignificantly smaller footprint than prior art devices or even the drivemechanisms 100, 500, 1000 of the other embodiments herein.

For the purposes of this disclosure and its claims, when used inconnection with biasing members, be it a specific embodiment of biasingmembers, such as springs, or the general use of the term “biasingmembers,” the terms “parallel” are to be interpreted as they would bythose of skill in the art. That is, the terms “series,” “in series,” or“disposed in series” is to be interpreted as springs disposed andoperating as they would when connected end to end, and the terms“parallel,” “in parallel,” or “disposed in parallel” is to beinterpreted as springs disposed and operating as they would in aside-by-side relationship.

Those of skill in the art will appreciate that for biasing membersdisposed in series, the inverse of equivalent spring constant will equalthe sum of the respective inverses of the spring constants of theindividual biasing members. In contrast, the equivalent spring constantof biasing members 2106, 2122 in a parallel relationship will be the sumof the spring constants of the individual biasing members. Similarly,the dispensing force exerted by the biasing members 2106, 2122 in aparallel relationship will be the sum of the forces exerted by thebiasing members 2106, 2122 individually. As a result, the use of biasingmembers 2106, 2122 disposed in parallel provides the desired dispensingforce in a substantially more compact package, allowing the drivemechanism 2100 to be more compact than the embodiments of FIGS. 1A-9C.By extension, the use of biasing members 2106, 2122 disposed in parallelmay allow the entire drug pump 2010 to be substantially more compactthan an arrangement wherein the biasing members are disposed in series.

In this embodiment, the biasing members 2106, 2122 are in the form of apair of concentrically disposed compression springs. Alternatearrangements are envisioned, however. For example, one or more of thebiasing members could alternately, for example, be tension springs,depending upon the structure of the components of the drive mechanism.Moreover, in the illustrated drive mechanism 2100, the biasing members2106, 2122 are disposed concentrically with respect to each other andthe piston 2100. In an alternate embodiment, however, the biasingmembers may be alternately disposed, as, by way of example only, in aside by side arrangement, or on opposite sides of the piston. In stillfurther embodiments, three or more biasing members could be provided anddisposed in parallel in any appropriate configuration. It will furtherbe appreciated, that an additional biasing member may be provided anddisposed in series with one or more of the parallelly disposed biasingmembers. For example, in an embodiment where the piston includes anextension, similar to the piston extension 102 of the embodiment ofFIGS. 1A-4E, for example, an additional biasing member may be providedto engage the piston extension.

Returning now to the embodiment of FIGS. 10A-14B, the drive mechanism2100 includes an end-of-dose indicator 2133. The end-of-dose indicator2133 includes a switch interconnect 2132 and a contact sleeve assembly2120 adapted for movement with the piston 2110. Piston 2110 has aninterface surface 2112 that is capable of contacting or otherwisebearing upon plunger seal 2060 to force drug fluid out of barrel 2058through the fluid pathway connection 2300 for delivery to a patient. Inorder to provide access of the end-of-dose indicator 2133 to theinterior of the drive housing 2130 includes an access window 2131, thesignificance of which will be described further below.

The contact sleeve assembly 2120 of the embodiment illustrated in FIGS.11-13C includes a pair of telescoping sleeves 2124, 2126. The firstsleeve 2124 is adapted for movement with the piston 2110 as the pistonbiasing members 2106, 2122 are deenergized. A distal, generally radiallyextending flange 2124A of the first sleeve 2124 is disposed subjacentthe head 2111 of the piston 2110. In this way, one or both of thebiasing members 2106, 2122 bear against the flange 2124A, which bearsagainst the piston head 2111 to impart axial movement to the piston2110. The second sleeve 2126 is slidably coupled to the first sleeve2124, the first sleeve 2124 sliding distally outward from the secondsleeve 2126. In order to permit the second sleeve 2126 to travel withthe first sleeve 2124 when the first sleeve 2124 is fully extended fromthe second sleeve 2126, a coupling structure is provided. In theillustrated embodiment the sleeves 2124, 2126 include respective flanges2124B, 2126A that engage as the proximal end of the first sleeve 2124approaches the distal end of the second sleeve 2126 (see FIG. 13A) tocause the second sleeve 2126 to likewise move in an axial direction withthe piston 2110 (see FIG. 13C).

It will be appreciated, however, that alternate arrangements areenvisioned. By way of example only, the first sleeve 2124 couldalternatively be integrally formed with the piston 2110. In this way,the first sleeve 2124 formed with the piston 2110 would telescopeoutward from a second sleeve 2126 in a manner similar to that describedabove. Moreover, while the sleeve assembly 2120 has been described asincluding a pair of telescoping sleeves, alternate numbers of sleevesmay be used, such as three or more telescoping sleeves. The number ofsleeves may be dependent upon the cooperative structures, however, suchas the relative dimensions of the drive housing 2130, and the travel ofthe piston 2110. For example, in an embodiment utilizing a smaller drivehousing, but having a similar piston travel, three or more telescopingsleeves may be desirable. In some embodiments where multiple sleeves areprovided about the biasing members 2106, 2122, and the biasing members2106, 2122 are in the form of compression springs, such as shown in theillustrated embodiment, the springs in a compressed, energized state mayhave a length equal to the untelescoped sleeves 2124, 2126, yet have anuncompressed, deenergized length that is equal to the length of thetelescoped sleeves. Further, while the end-of-dose indicator 2133 isdescribed in connection with a drive mechanism 2100 including aplurality of biasing members disposed in parallel, those of skill in theart will appreciate that the end-of-dose indicator 2133 could also beutilized in connection with a drive mechanism including a single biasingdevice or a plurality of biasing members disposed in series and/orparallel.

As the sleeve assembly 2120 moves axially outward, the proximal end2126B of the sleeve assembly 2120 passes the window 2131 of the drivehousing 2130. In the illustrated embodiment in particular, as the secondsleeve 2126 moves axially outward, the proximal end 2126B of the secondsleeve 2126 passes the window 2131 of the drive housing 2130.

The switch interconnect 2132 includes a sensor 2134 and an electroniccoupling 2136 to the power and control system 2400. At least a portionof the sensor 2134 is disposed adjacent the window 2131, and is adaptedto identify a change in the presence of the contact sleeve assembly 2120proximal to the window 2131 within the drive housing 2130. For example,in the illustrated embodiment, the sensor 2134 may read that the sleeveassembly 2120 is no longer present proximal to the window 2131.

In order to better illustrate the relationship of the sensor 2134 andthe sleeve assembly 2120 during movement of the sleeve assembly 2120,portions of the sleeve assembly 2120 are broken away in FIGS. 13A-13B;in FIGS. 14A-14B, the housing 2130, sleeve 2126, biasing members 2106,2122, and end-of-dose indicator 2133 are shown in cross-section takenalong line 14-14 in FIG. 11. In the illustrated embodiment, the sleeveassembly 1120 is disposed adjacent the window 2131 when the piston 2110is in the retracted first position (see FIG. 13A), and as the sleeveassembly 1120 begins to telescope outward with the piston 2110 (seeFIGS. 13B and 14A). Conversely, the sleeve assembly 1120 is not disposedadjacent the window 2131 when the piston 2110 is in a fully extendedsecond position (see FIGS. 13C and 14B). As the proximal end 2126B ofthe second sleeve 2126 passes the window, the switch interconnect 2132identifies that the sleeve assembly has passed the window 2131, and thatthe end of dose has occurred, and provides that information to the powerand control system 2400. The electronic coupling 2136 may be of anyappropriate design. In the illustrated embodiment, for example, thesensor 2134 connects directly to a PCB board 2138.

The switch interconnect 2132 illustrated includes a mechanical sensor2134 in the form of a pivotably mounted trigger 2135, in essence, anon/off mechanical switch. The trigger 2135 is disposed in a firstposition in contact with the sleeve assembly 2120 when the piston 2110is in a retracted first position. As the piston 2110 moves outward fromthe drive housing 2130, the trigger 2135 slides along the telescopingsleeve assembly 2120 until such time as the proximal end 2126B of thesecond sleeve 2126 passes the window 2131, that is, the trigger 2135. Asthe second sleeve 2126 passes the trigger 2135, the trigger 2135 movesto a second position. The movement of the trigger 2135 to the secondposition results in the electronic coupling 2135 providing a signalindicating the end of dose to the power and control system 2400.

The switch interconnect 2132 may be of any appropriate design, however.For example, the switch interconnect 2132 may include a sensor of anelectromechanical nature, such as the one illustrated in FIGS. 10A-14B,or a sensor of an electrical nature, such as, for example, an opticalreader or sensor. Additionally or alternatively, the switch interconnect2132 may utilize an ultrasonic sensor, a capacitive sensor, a magneticsensor, or a number of other types of sensors. Accordingly, the sensormay not require physical contact with the corresponding referencecomponent. In an embodiment including an optical sensor, the sensor mayread when the presence or absence of the sleeve assembly 2120, forexample, reading the interior of the drive housing 2130 opposite thewindow 2131. The sensor may be configured to additionally oralternatively identify at least one of when the sleeve assembly isdisposed subjacent the window and when the sleeve assembly is notdisposed subjacent the window, the relative motion of the sleeveassembly with reference to the window or another reference component,the stoppage of such motion, and the rate or change of rate of motion.

As described above, the switch interconnects and sensors of theend-of-dose indicator may be configured in a myriad of ways to functionwithin the drive mechanisms of the present invention. The switchinterconnects and sensors may initially be connected (e.g., a closed orcomplete circuit) or disconnected (e.g., an open or broken circuit) froma PCB board. Additionally, the sensor may utilize a trigger thatdirectly or indirectly engages with a PCB board to permit transmissionof a signal to the power control system. Furthermore, the drivemechanism may include more than one switch interconnect, sensor and/ortrigger, for example, for functional redundancy or operationalrobustness.

FIGS. 15 and 16A-16B, show another embodiment of the drive mechanism3100 which includes an end-of-dose indicator 3133. The end-of-doseindicator 3133 includes a switch interconnect 3132 and a contact sleeveassembly 3120 adapted for movement with the piston. As described abovewith reference to the embodiments shown in FIGS. 10A-14B, the piston hasan interface surface that is capable of contacting or otherwise bearingupon plunger seal to force drug fluid out of barrel through the fluidpathway connection for delivery to a patient. In order to provide accessof the end-of-dose indicator 3133 to the interior of the drive housing3130, the drive housing 3130 includes an access window 3131. In at leastone embodiment, the drive housing 3130 includes more than one accesswindow 3131 to permit pass-through of more than one switch interconnect,sensor and/or trigger to, for example, interface with the sleeveassembly 3120. In order to better illustrate the relationship of theend-of-dose indicator 3133 and the sleeve assembly 3120 during movementof the sleeve assembly 3120, FIGS. 16A and 16B show the housing 3130,sleeve 3126, biasing members 3106, 3122, and end-of-dose indicator 3133in cross-section taken along line 15-15 in FIG. 15, before and afteractuation, respectively. The PCB board 3138 is included in this view ofthe drive mechanism 3100 to show the interaction between the end-of-doseindicator 3133 and the PCB board 3138.

The end-of-dose indicator 3133 illustrated includes a sensor 3134 thatincludes a mechanical, pivotably mounted trigger 3135, in essence, anon/off mechanical switch. In at least one embodiment, the end-of-doseindicator 3133 has more than one trigger 3135 mounted through more thanone corresponding window 3131 of the drive mechanism 3100, forfunctional redundancy and/or operational robustness. Each of thetriggers 3135 is disposed in a first position in contact with the sleeveassembly 3120, particularly the sleeve 3126 thereof, when the piston3110 is in a retracted first position, illustrated in FIG. 16A. As thepiston 3110 moves outward from the drive housing 3130, the triggers 3135slide along the telescoping sleeve assembly 3120 until such time as theproximal end of the second sleeve 3126 passes the windows 3131, that is,the triggers 3135. As the second sleeve 3126 passes at least one of thetriggers 3135, the trigger 3135 moves to a second position, illustratedin FIG. 16B. The movement of the trigger 3135 to the second positionresults in the transmission of a signal indicating the end of dose tothe power and control system. In this configuration, movement of atleast one trigger 3135 will cause the transmission of the signal tooccur.

Those of skill in the art will appreciate that in some configurations,there is the possibility that the disposal of the spring 3122 subjacentthe window 3131 following axial movement of the sleeve 3126 may inhibitactuation of the sensor 3134 of the switch interconnect 3132, forexample, by inhibiting movement of the trigger 3135 to an actuatedposition. Although the sensor 3134, or trigger 3135, may be preventedfrom actuation only temporarily, such delay may result in acorresponding delay in the indication of the end of the dose.Accordingly, the inclusion of two or more sensors 3134 or triggers 3135may provide a desirable redundancy. Moreover, the windows 3131 andsensors 3134 may be positioned to maximize the opportunity for actuationof at least one of the triggers 3135 concurrently with the end of thedose delivery. Because more than one trigger 3135 is utilized in thisconfiguration, the end-of-dose indicator 3133 provides functionalredundancy to ensure that an accurate signal is transmitted to the powerand control system.

For the purposes of this disclosure and the appended claims, thetransmission of a signal means the provision of an indication that theend of dose has occurred. That transmission may be associated with amechanical movement, for example, the engagement or disengagement, or anelectrical signal, for example, the provision of an electrical signal orconnection, or the discontinuation of an electrical signal orconnection, or a combination of such transmissions.

In at least one embodiment of the configuration shown in FIGS. 15-16B,the switch interconnects 3132 directly engage with a PCB board 3138 topermit transmission of a signal to the power control system. The switchinterconnects 3132 may further be configured to initially be connected(e.g., a closed or complete circuit) or disconnected (e.g., an open orbroken circuit) from a PCB board 3138, though the embodiment shown inFIGS. 16A-16B shows the switch interconnects 3132 initially connected tothe PCB board 3138, that is, prior to the end of dose. As the secondsleeve 3126 passes at least one of the triggers 3135, as shown in thetransition from FIG. 16A to FIG. 16B, the trigger 3135 moves to a secondposition, namely, a distance shown as ‘D1’ in FIG. 16B. The movement ofthe trigger 3135 to the second position results, in at least oneembodiment, in a disconnection of the switch interconnect 3132 from thePCB board 3138 and the resulting transmission of a signal indicating theend of dose to the power and control system. While the illustrateddesign shows the switch interconnect 3132 directly engaged with the PCBboard 3138, it will be appreciated that the switch interconnect 3132could alternatively or additionally engage one or more intermediateconductive or nonconductive structures.

The end-of-dose indicator 3133, triggers 3135, and PCB board 3138 mayalternatively be configured, as would be readily appreciated by anordinarily skilled artisan, to cause a connection there-between upon themovement of the trigger 3135 to the second position. By way of exampleonly, a trigger may be toggled such that the switch interconnect is notin communication with the PCB board prior to the end of dose, movementof the trigger at the end of dose yielding a connection directly with orconveyed to the PCB board. Additionally, as described below, theconnection and disconnection (or vice versa) between the switchinterconnects 3132 and the PCB board may be utilized to provideincremental status indication.

The end-of-dose indicator 3133 may be of any appropriate design andformed of any appropriate material or materials and by any appropriatefabrication method. The illustrated switch interconnect 3132 may beformed in whole or in part of a conductive material, for example. In anarrangement wherein an electrical connection occurs when the trigger3135 is in the position illustrated in FIG. 16A and electricalconnection is discontinued when the trigger 3135 is in the positionillustrated in FIG. 16B, for example, at least a portion of the switchinterconnect 3132 disposed to engage with the PCB board 3138 may beformed of or coated with a conductive material. Conversely, in anarrangement wherein no electrical connection occurs when the trigger3135 is in the position illustrated in FIG. 16A and electricalconnection occurs when the trigger 3135 is in the position illustratedin FIG. 16B, for example, at least a portion of the switch interconnect3132 disposed to engage with the PCB board 3138 may be formed of orcoated with an insulative material.

Although illustrated as an electromechanical arrangement that reads theposition of a telescoping sleeve, any appropriate arrangement may beprovided to read the relative position of any appropriate component, theend-of-dose indicator providing a signal to the power and control systemto indicate that all of the drug has been administered. Additionally,the switch interconnects and corresponding contacts and/or referencecomponent may be utilized to provide incremental status indication inaddition to an end-of-dose indication. For example, in the switchinterconnect arrangement described above with reference to FIGS. 10A-14Bor FIGS. 15-16B, the switch interconnect 2132, 3132 may be anelectromechanical sensor configured to recognize a number of bumps,ridges, or grooves, in the corresponding sleeve 2126, 3126 or any otherreference component, the contact with which permits the switchinterconnect to signal an incremental status indication (e.g., deliveryinitiation, amount of volumes delivered, duration of plunger travel,etc.) and a final end-of-dose indication. As described herein, similarincremental status indication may be provided in this configuration byutilizing a different type of sensor arrangement. For example, theswitch interconnect 2132, 3132 may be an optical sensor configured torecognize a number of markings on the corresponding sleeve 2126, 3126 orany other reference component. As the optical sensor recognizes thenumber of markings, it permits the switch interconnect to signal anincremental status indication (e.g., delivery initiation, amount ofvolumes delivered, duration of plunger travel, etc.) and a finalend-of-dose indication. Any appropriate arrangement may be provided toread the relative position of a number of markings, ridges, grooves, orrespective indicators on any appropriate reference component, andrecognition of such indicators by the switch interconnect permits it toprovide a signal to the power and control system to indicate theincremental status of drug delivery, including the final status that allof the drug has been administered. As would be appreciated by anordinarily skilled artisan in the relevant arts, the indicators may notnecessarily be defined aspects on a reference component, and the switchinterconnects may be configured to recognize the actual travel of thereference component itself. The switch interconnects may thus beconfigured to recognize the rate of change, the distance of travel, orother related measurements in the actual travel of the referencecomponents and enable a signal to the power and control system toprovide the user with such information or feedback.

It will be appreciated by those of skill in the art that the embodimentsof the present invention provide the necessary drive force to push aplunger seal and a drug fluid within a drug container, while reducing orminimizing the drive mechanism and overall device footprint.Accordingly, the present invention provides a drive mechanism which maybe utilized within a more compact drug delivery pump device. Theembodiments of the present invention may similarly be utilized toprovide additional force, as may be needed for highly viscous drugfluids or for larger volume drug containers.

The embodiments shown and detailed herein disclose only a few possiblevariations of the present invention; other similar variations arecontemplated and incorporated within the breadth of this disclosure.

The drive mechanism may further include one or more contact surfaceslocated on corresponding components. Such contact surfaces may beelectrical contact surfaces, mechanical contact surfaces, orelectro-mechanical contact surfaces. Such surfaces may initially be incontact and caused to disengage, or initially be disconnected and causedto engage, to permit a signal to be sent to and/or from the powercontrol system 2400.

A fluid pathway connection, and specifically a sterile sleeve of thefluid pathway connection, may be connected to the cap and/or pierceableseal of the drug container. A fluid conduit may be connected to theother end of the fluid pathway connection which itself is connected tothe insertion mechanism such that the fluid pathway, when opened,connected, or otherwise enabled travels directly from the drugcontainer, fluid pathway connection, fluid conduit, insertion mechanism,and through the cannula for drug delivery into the body of a user. Thecomponents which constitute the pathway for fluid flow are nowassembled. These components may be sterilized, by a number of knownmethods, and then mounted either fixedly or removably to an assemblyplatform or housing of the drug pump, as shown in FIG. 1B.

Certain optional standard components or variations of drive mechanism100 or drug pump 10 are contemplated while remaining within the breadthand scope of the present invention. For example, upper or lower housingsmay optionally contain one or more transparent or translucent windows18, as shown in FIG. 1A, to enable the user to view the operation of thedrug pump 10 or verify that drug dose has completed. Additionally, thedrug pump 10 may contain an adhesive patch 26 and a patch liner 28 onthe bottom surface of the housing 12. The adhesive patch 26 may beutilized to adhere the drug pump 10 to the body of the user for deliveryof the drug dose. As would be readily understood by one having ordinaryskill in the art, the adhesive patch 26 may have an adhesive surface foradhesion of the drug pump to the body of the user. The adhesive surfaceof the adhesive patch 26 may initially be covered by a non-adhesivepatch liner 28, which is removed from the adhesive patch 26 prior toplacement of the drug pump 10 in contact with the body of the user.Removal of the patch liner 28 may further remove the sealing membrane254 of the insertion mechanism 200, opening the insertion mechanism tothe body of the user for drug delivery (as shown in FIG. 1C).

Similarly, one or more of the components of drive mechanism 100 and drugpump 10 may be modified while remaining functionally within the breadthand scope of the present invention. For example, as described above,while the housing of drug pump 10 is shown as two separate componentsupper housing 12A and lower housing 12B, these components may be asingle unified component. Similarly, while electrical contact 134 isshown as a separate component from contact sleeve 140, it may be aunified component printed onto the ring surface of the contact sleeve140. As discussed above, a glue, adhesive, or other known materials ormethods may be utilized to affix one or more components of the drivemechanism and/or drug pump to each other. Alternatively, one or morecomponents of the drive mechanism and/or drug pump may be a unifiedcomponent. For example, the upper housing and lower housing may beseparate components affixed together by a glue or adhesive, a screw fitconnection, an interference fit, fusion joining, welding, ultrasonicwelding, and the like; or the upper housing and lower housing may be asingle unified component. Such standard components and functionalvariations would be appreciated by one having ordinary skill in the artand are, accordingly, within the breadth and scope of the presentinvention.

It will be appreciated from the above description that the drivemechanisms and drug pumps disclosed herein provide an efficient andeasily-operated system for automated drug delivery from a drugcontainer. The novel embodiments described herein provide integratedstatus indication to provide feedback to the user. The novel drivemechanisms of the present invention may be directly or indirectlyactivated by the user. For example, in at least one embodiment thelockout pin(s) which maintain the drive mechanism in its locked,energized state are directly displaced from the corresponding lockoutgrooves of the piston 110 by user depression of the activationmechanism. Furthermore, the novel configurations of the drive mechanismand drug pumps of the present invention maintain the sterility of thefluid pathway during storage, transportation, and through operation ofthe device. Because the path that the drug fluid travels within thedevice is entirely maintained in a sterile condition, only thesecomponents need be sterilized during the manufacturing process. Suchcomponents include the drug container of the drive mechanism, the fluidpathway connection, the sterile fluid conduit, and the insertionmechanism. In at least one embodiment of the present invention, thepower and control system, the assembly platform, the control arm, theactivation mechanism, the housing, and other components of the drug pumpdo not need to be sterilized. This greatly improves themanufacturability of the device and reduces associated assembly costs.Accordingly, the devices of the present invention do not requireterminal sterilization upon completion of assembly. A further benefit ofthe present invention is that the components described herein aredesigned to be modular such that, for example, housing and othercomponents of the pump drug may readily be configured to accept andoperate drive mechanism 100, drive mechanism 500, or a number of othervariations of the drive mechanism described herein.

Manufacturing of a drug pump includes the step of attaching both thedrive mechanism and drug container, either separately or as a combinedcomponent, to an assembly platform or housing of the drug pump. Themethod of manufacturing further includes attachment of the fluid pathwayconnection, drug container, and insertion mechanism to the assemblyplatform or housing. The additional components of the drug pump, asdescribed above, including the power and control system, the activationmechanism, and the control arm may be attached, preformed, orpre-assembled to the assembly platform or housing. An adhesive patch andpatch liner may be attached to the housing surface of the drug pump thatcontacts the user during operation of the device.

A method of operating the drug pump includes the steps of: activating,by a user, the activation mechanism; displacing a control arm to actuatean insertion mechanism; and actuating a power and control system toactivate a drive control mechanism to drive fluid drug flow through thedrug pump. The method may further include the step of: engaging anoptional on-body sensor prior to activating the activation mechanism.The method similarly may include the step of: establishing a connectionbetween a fluid pathway connection to a drug container. Furthermore, themethod of operation may include translating a plunger seal within thedrive control mechanism and drug container to force fluid drug flowthrough the drug container, the fluid pathway connection, a sterilefluid conduit, and the insertion mechanism for delivery of the fluiddrug to the body of a user. The method of operation of the insertionmechanism and the drug pump may be better appreciated with reference toFIGS. 4A-4E, as described above.

Throughout the specification, the aim has been to describe the preferredembodiments of the invention without limiting the invention to any oneembodiment or specific collection of features. Various changes andmodifications may be made to the embodiments described and illustratedwithout departing from the present invention. The disclosure of eachpatent and scientific document, computer program and algorithm referredto in this specification is incorporated by reference in its entirety.

What is claimed is:
 1. A drug pump drive mechanism for use incooperation with a drug container including a plunger seal and a powerand control system, the drive mechanism comprising: a drive housingdefining an axis; a piston disposed for movement from at least aretracted first position to an extended second position along said axis,the piston adapted to impart movement to the plunger seal within thedrug container; at least one biasing member disposed and adapted tocause movement of the piston from the retracted first position to theextended second position as the biasing member moves from an energizedfirst position to a deenergized second position; a sleeve assemblydisposed at least partially within the drive housing, at least a portionof the sleeve assembly being adapted to move along said axis with thepiston; and an end-of-dose indicator, the end-of-dose indicatorincluding a switch interconnect, the switch interconnect including amechanical sensor adapted to selectively engage a portion of the sleeveassembly as a result of the movement of the piston from the retractedfirst position to the extended second position, the switch interconnectfurther being adapted to selectively engage the power and control systemas a result of the engagement or disengagement of the sensor.
 2. Thedrug pump drive mechanism as claimed in claim 1, wherein the switchinterconnect engages the power and control system when the triggerengages the sleeve assembly.
 3. The drug pump drive mechanism as claimedin claim 1, wherein the switch interconnect is disposed to selectivelyengage a PCB board of the power and control system dependent upon theposition of the trigger relative to the sleeve assembly.
 4. The drugpump drive mechanism as claimed in claim 1, wherein the sleeve assemblyhas a trailing edge, and the mechanical trigger is disposed in a firstposition when the piston is in the retracted first position and a secondposition when the trailing edge of the sleeve assembly moves axiallypast the mechanical trigger.
 5. The drug pump drive mechanism as claimedin claim 1, wherein the sleeve assembly includes a plurality oftelescoping sleeves.
 6. The drug pump drive mechanism as claimed inclaim 1 including at least two biasing members, the sleeve assemblybeing disposed about the at least two biasing members.
 7. The drug pumpdrive mechanism as claimed in claim 1, wherein the at least one biasingmember includes a pair of compression springs.
 8. The drug pump drivemechanism as claimed in claim 7, wherein the compression springs areconcentrically disposed.
 9. The drug pump drive mechanism as claimed inclaim 1, wherein the mechanical sensor includes a pivotably mountedtrigger.
 10. The drug pump drive mechanism as claimed in claim 1,wherein the mechanical sensor includes at least two pivotably mountedtriggers, the switch interconnect further being adapted to selectivelyengage the power and control system as a result of the engagement ordisengagement of any one of the at least two pivotably mounted triggers.11. A drug pump comprising: a drug container including a plunger seal; apower and control system; a needle insertion mechanism; a fluid pathwayconnection; and a drive mechanism including: a drive housing defining anaxis; a piston disposed for movement from at least a retracted firstposition to an extended second position along said axis, the pistonadapted to impart movement to the plunger seal within the drugcontainer; at least one biasing member disposed and adapted to causemovement of the piston from the retracted first position to the extendedsecond position as the biasing member moves from an energized firstposition to a deenergized second position; a sleeve assembly disposed atleast partially within the drive housing, at least a portion of thesleeve assembly being adapted to move along said axis with the piston;and an end-of-dose indicator, the end-of-dose indicator including aswitch interconnect, the switch interconnect including a mechanicalsensor adapted to selectively engage a portion of the sleeve assembly asa result of the movement of the piston from the retracted first positionto the extended second position, the switch interconnect further beingadapted to selectively engage the power and control system as a resultof the engagement or disengagement of the sensor; wherein the power andcontrol system initiates an end-of-dose indication as a result of theselective engagement of the switch interconnect.
 12. The drug pump asclaimed in claim 11, wherein the switch interconnect engages the powerand control system when the trigger engages the sleeve assembly.
 13. Thedrug pump as claimed in claim 11, wherein the switch interconnect isdisposed to selectively engage a PCB board of the power and controlsystem dependent upon the position of the trigger relative to the sleeveassembly.
 14. The drug pump as claimed in claim 11, wherein the sleeveassembly has a trailing edge, and the mechanical trigger is disposed ina first position when the piston is in the retracted first position anda second position when the trailing edge of the sleeve assembly movesaxially past the mechanical trigger.
 15. The drug pump as claimed inclaim 11, wherein the sleeve assembly includes a plurality oftelescoping sleeves.
 16. The drug pump as claimed in claim 11 includingat least two biasing members, the sleeve assembly being disposed aboutthe at least two biasing members.
 17. The drug pump as claimed in claim11, wherein the at least one biasing member includes a pair ofcompression springs.
 18. The drug pump as claimed in claim 11, whereinthere is a delay between the selective engagement of the switchinterconnect and the initiation of the end-of-dose indication.
 19. Thedrug pump as claimed in claim 11, wherein the mechanical sensor includesa pivotably mounted trigger.
 20. The drug pump as claimed in claim 11,wherein the mechanical sensor includes at least two pivotably mountedtriggers, the switch interconnect further being adapted to selectivelyengage the power and control system as a result of the engagement ordisengagement of any one of the at least two pivotably mounted triggers.